


Fall 2016 Smutmas Collection

by PineWreaths



Series: Smutmas [2]
Category: Gravity Falls
Genre: F/F, F/M, Gravity Scars AU, Multi, Pinescifica, pinecest - Freeform
Language: English
Status: Completed
Published: 2016-08-18
Updated: 2016-08-28
Packaged: 2018-08-09 13:17:06
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 9
Words: 21,924
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7803424
Author URL: https://archiveofourown.org/users/PineWreaths/pseuds/PineWreaths
Summary: <blockquote class="userstuff">
              <p>A collection of various prompt-based stories, all of them smutty and in no particular chronological/relational order. The tags refer to at least one story in the collection containing that subject; Let me know if you want me to post them separate in case there is a particular tagged subject you want to avoid while still being able to read the rest.</p>
            </blockquote>





	1. The Flood

“Oh god, oh god, Dipper, no!”

Mabel’s cries came out above the rushing water, the shrill edge of terror catching out as Dipper gasped for air. He thrashed, kicking again as he pulled the suitcase from the back of their hatchback, twisting his whole body to try and anchor himself on the edge of the rock the car had floated into. His elbow caught around a slight peak of rock, and he used the leverage to heave himself out of the rushing and dirt-brown waters.

Mabel came running over, and her hand was under his, helping pull him to his feet as he stumbled back. There was a shriek of metal, and the car door that had wedged between a crack in the stone finally gave way. The twins stood there, panting, as they watched their car float away, into the roaring river that had only been a creek alongside the road scarcely an hour ago.

“Are-are you ok?” he gasped, coughing out the words and looking at Mabel’s worried expression as he tried to catch his breath. She nodded, pulling him farther up the boulder and onto the weed-ridden bluff, away from the rushing water filled with entire floating trees.

Then there was a breath of warmth against the raging cold, as Mabel pulled him up and planted a breathy kiss on his cheek. Dipper started, and turning to look at her he could see the tears streaking her face. “Dip, I-I was so worried, and the rushing water and the car, oh god, the car, I-”

Dipper said nothing, the guilt edging forward as he felt his face flush, his sudden surge in his chest at her kiss matching the rushing icy wave of shame at jeopardizing himself like that. Of _course_ Mabel would be worried for him, and he’d gone back into the flood, for what?

He looked at the suitcase, dripping water from the storm. _So much for a change of clothes,_ he thought with regret. He reached into the uppermost pocket, the one that had only been splashed by the looks of it rather than being saturated like the rest of the case. Murmuring a quiet prayer and with held breath, he let out a whooshing sigh as he came up with a flashlight, an emergency one with a little hand crank on the side.

Mabel cracked a little smile as some furious elbow grease created a patch of light; just in time, as the last fading beams of the sunset fighting through the stormclouds had winked away a few minutes ago, and the remaining light was dying fast. She lifted the suitcase, leaving Dipper to light the way as they started hiking through the untamed grass and brambles.

“I think I saw a cabin in the woods a little ways back or so. No lights on, but it would be some good shelter, and it was uphill so it should be safer than staying here.” Mabel nodded, and her grasping hand caught Dipper’s. He gave her a little funny smile, interlacing her fingers with his as they made their way through ferns and under the sodden boughs of cedars.

Now and then they had to stop, as the sodden loam gave way under an errant sneaker, slipping and stumbling towards the surging river below before the firm grasp of a sibling stopped their fall. The water was still rising, and more than once they had to cut further uphill, into even thicker bushes and underbrush, to avoid the swirling waters. Once, they thought they heard a distant emergency siren, but after a few minutes of waiting, the howling wind and water drowned out any traces.

Finally, Dipper and Mabel both could make out the sharp angle of a dark roof against the trees. The light from the flashlight could barely make out the structure, and a flat area that had once been a parking lot was overgrown with weeds and errant rocks that had been disturbed from the head-high cliff that formed the backdrop for the cabin.

They both sighed in relief, although Dipper’s sigh became a groan as he let go of Mabel’s hand and jogged ahead to check the building.

“What is it, Dipper?”

Dipper said nothing, and instead shone the light upwards. The roof was riddled with holes, in several cases with broken and dead branches punching through them, and the interior of the shack was moist at best, and covered with puddles over more than half of the floorboards.

Mabel forced herself to smile, shooting a glance towards the still-distant waters, and said “Well, it’s no vacation destination, that’s for sure. Still, beats whitewater rafting on top of your car, eh?”

This caused Dipper to groan again, this time in worry, and Mabel quickly reassured him. “Hey, Dip, don’t worry, ok? Floods are totally covered under insurances and stuff. Big smashy cryptids, not so much, but this you should be fine. Or, was it…” Her voice trailed off, as she realized that wasn’t what Dipper was worried about. His shoulders were hunched, as he waved his arm all around them, frustration giving an edge to his words.

“Mabel, the-this-I-ugh, I, I’m sorry. I thought we’d get a chance to dry off, get warm. I hoped there might be someone, somebody here who could-”

She interrupted his statement with a squeeze on his arm. “Dip, it’s _ok_. You didn’t buy and abandon a cabin in the middle of nowhere, right? And besides, you’ve got me.” She punctuated the statement with a smile, and Dipper couldn’t help but return it.

“Yeah, you’re right.” He sighed, grinning back even as she saw his eyes flick towards the water below.

“How about you go start us a fire, Sir Dippingsauce? I’ll see if I can find some dry firewood.”

He nodded, and fished through the suitcase, pushing aside waterlogged dresses of Mabel’s and shirts and pants of his own, until he found the tiny survival kit in an old camera film case. Pulling out the hurricane matches, he carefully curated the little pieces of kindling and flammable bits and ends he could find that weren’t soaked. With a deep, cautiously-held breath, he lit the match with a flaring whoosh of heat and light. After a painful three seconds, the tinder caught, and he had to avoid letting his sigh of relief snuff the infant fire. A bit of careful tending, aided with the arrival of more kindling and branches Mabel had found in and around the nearby trees, and they had a crackling fire under the one intact corner of the cabin; Dipper had reasoned that the place was condemned anyways, so it wouldn’t hurt to take advantage of the one corner where the roof _hadn’t_ caved in yet.

He was sitting, warming up his feet as his boots hung on two sticks over the fire, roasting them enough to dry them out but not enough to scorch the leather or melt the soles. Mabel had strung up a makeshift clothesline just out of reach of the flames themselves to dry clothes, and had already thrown one of her lighter dresses and a pair of Dipper’s shorts over to dry as well.

Dipper was unfolding the mostly-dry wool blanket she’d pulled out, and didn’t see her again until he’d finished getting it pulled into such a position that they could both sit and cover themselves partyway with it. She had said something about ‘chafing’, but Dipper was busy and had partly tuned out what she was saying.

So when he looked up, his brain wasn’t expecting the little white flash of shock and heat he felt, as he saw Mabel had removed her shirt, pants, and bra, hanging them over the clothesline. She turned back to him, her long curls falling and almost covering her little brown nipples, and gave a shy smile.

Dipper quickly looked away, clearing his throat in embarrassment, when he heard his sister’s voice.

“Dip, you too. Don’t want to die of cold, right?”

Dipper looked back, seeing her gaze, with that same small smile on her lips, and he let out a strangled reply.

“But, we-the fire’s not warm enough for-”

Mabel just stood there, crossing her arms over her breasts, and abruptly the back end of Dipper’s psyche finally caught up with current events and kicked him to shut up and strip. He did, removing everything but his cotton boxers, and flopping them over the laden clothesline. Then he went to sit next to Mabel on the blanket, pulling it up as much as they could until only their upper torsos were uncovered.

Mabel wiggled and snuggled herself up to Dipper; the skin-on-skin contact was icy cold for a moment, then surged into heat. Dipper’s hands roamed for a moment, trying to find a spot to rest that wasn’t on a naked pert of his sibling, until they made their way down to just rest on top of the damp wool.

His sister let out a sigh, and he smiled. There was a few long minutes of lovely warmth from both fire and twin, and then he heard Mabel say, in almost a whisper.

“Dipper, when you went back into the car…when the river surged like that, I…”

He sighed again, mentally kicking himself for endangering his life like that and possibly leaving his sibling an only child. “Mabes, I’m-”

“Dip, I realized, when I thought I might lose you, that-that…I love you, Dip.”

“I love you too, Mabes,” he said, an almost automatic reply at this point.

“No, Dip, I _really_ love you. Like, could-spend-the-rest-of-my-life-with-you love you.”

Dipper felt his heart surge into his chest, and could feel Mabel stiffen as she waited for his reply. He could only see part of her face from how she was resting on his shoulder, but her bitten lip indicated how anxious she was about possibly oversharing like this.

Dipper took a deep breath, and sat up. Mabel shot up as well, looking at him with uncertainty in her eyes, until Dipper smiled. “Mabel, I love you too. And I could definitely spend the rest of my life with you.”

Then the part of his mind he always saw as more ‘Mabel’ than ‘Dipper’ pushed past rationality, and urged him to move his head forward, his mouth slightly open as he waited to see if-

Mabel’s lips met his like a crashing wave, the heat of her mouth like an inferno. He felt his hands reach behind her, pulling her deeper into the kiss as she let out a hum of loving approval. Cracking open his damp eyes, he could see her gaze was shining with tears as well.

They held the kiss, and Dipper felt Mabel’s tongue nervously touch his lips, for just a moment. He opened his mouth further in response, and she slid her tongue in, the heat of her panting breath now lending heat and excitement to the rest of his body. The boxers soon were parted as he felt his erection growing through, to rub against the slight irritating abrasion of the cold wool.

His sister’s hands began to roam, from his naked back and down his sides, until the lump in the wool was felt. Breaking the kiss, she gave him a questioning look. When Dipper shrugged and gave her an awkward smile, Mabel tugged the cotton away, letting out a little gasp as his cock was revealed in the crackling firelight. She pulled the blanket away from herself as well, and Dipper could see the little pink-and-kitten panties for a moment, before she moved to straddle him.

She gave him one last look, her hair swept behind to shower down her smooth back, her nippled peaking in the cold and wet air. She had her hands on her thighs, rubbing his hardness along her through the barrier of her panties.She moved faster and faster, and Dipper could feel his pulse accelerate to match. Then, slowing and leaning back, she reached down to grab his shaft, and with her other hand she nudged aside the thin cotton.

Dipper leaned back, groaning, as he felt her rub along his shaft one more time, slowly, as he felt the wet heat from her excitement before she stopped, and slowly eased herself onto him.

Both twins groaned with pleasure, Dipper reaching forward to Mabel’s hips to pull her deeper onto him, as her hands migrated back up to her breasts, holding them as she began to rock, letting out little breathy gasps of pleasure as she rolled her hips back and forth on her brother’s hardness.

Dipper slowed, arching himself up slightly to urge Mabel to lean forward. As she did, he gently grabbed her wrists, moving her hands aside so he could gently lead a set of kisses around the nipples, and then onto them. She sighed happily as Dipper began to trail the kissed upwards, to the nape of her neck, and then the edge of her jaw, before meeting her mouth with hungry and deep breathy kisses.

Mabel returned them in kind, and Dipper could feel her begin to slow her rocking hips, instead angling more carefully as her breath began to catch, coming more and more quickly with the rising flush on her chest. Then there was a twitch, a clenching around his cock, and Dipper groaned as he came from the sensation. Mabel broke the kiss, to let out a low moan of pleasure, continuing to rock on his cock as she let out little violent shivers of pleasure.

Then they sat back, Mabel extricating herself to sit beside Dipper on the blanket. They were both breathing hard, but locked gazes. Dipper thought to say something, but instead stayed silent; no words needed to be said, and instead he just leaned forward and met Mabel’s kiss, as the pitter-patter of rain started to fade.

 

* * *

 

Dipper awoke with a groan, the first glints of light through the trees lancing through his closed eyes, and he sat up, stretching. The previous night went racing through his mind, and he began to feel the unpleasant sensation of worry.

_Was it all real? It’s not the first time I’ve had a, uh, particularly ‘vivid’ dream about Mabel, and the last thing I need it to tell her all about my love if her words were all in my head too-_

Then his train of thought jumped the tracks, as Mabel came into view. She was wearing her sundress she had dried by the fire, a thin and nearly-sheer floral print she normally wore over a white underdress. This time there was no underdress, and Dipper could clearly make out the shape of her breasts, the curve of her back, and the mischievous lip-biting smile as she watched Dipper notice all the details.

“Looks like the water’s receding, brobro. We made it.”

He got to his feet, pulling on his pair of now-dry shorts, before walking up to hug his sister from behind. She ran a hand back behind to run through Dipper hair as he leaned down to give her a kiss on the neck. She turned and met the kiss, and after a long moment they broke it away, leaving the two of them smiling at each other.

“I love you.”

**Notes for the Chapter:**

> Prompt, from @sprucepinecest: For Smutmas, the twins are caught in a major storm and thinking they might not survive they both confess their feelings. Then the storm passes and they realize they’re safe.


	2. Ford Experiment #40

“-and so under no circumstances should you kids ever be poking around in my lab. Why, there’s stuff that could kill a man! Some of it even has!”

Dipper, wide-eyed at even being allowed to glimpse the interior of the lab, just nodded in awestruck glee. Mabel, however, had already scooted around Grunkle Ford, and had pulled open one door of a grey cabinet. Dipper caught a glimpse of an engraved skull motif over the entire door before Ford was pushing past him, shouting “Wait, Mabel, don’t touch that!”

Mabel had her eyes glued to racks upon racks of small vials, filled with pink and purple fluids and small labels Dipper couldn’t make out from this distance. Ford snatched the handful Mabel had grabbed, quickly solving them haphazardly back onto a shelf, and slamming the door shut.

Mabel’s voice held an accusatory tone as she put her hands on her hips. “Grunkle Ford, what do the vials mean ‘extract of cow’ and ‘extract of squirrel?’”

Ford met her gaze, and cleared his throat as Dipper saw him take a half-step to the side, putting his body between his sister and some sort of mechanism with a large funnel on the top.

“It means an extract. Now, it’s all very sciency, so just don’t worry about it for now. I can explain later, but right now I need to go help Stan with his-”

“HEY SIXER!”

The shouting voice rang down the elevator shaft and into Ford’s study-turned-lab. Ford visibly flinched, and called back “Be there in a minute, Stan!” Then he turned back to the twins, giving them a very pointed finger-waggle as he re-locked the door. Dipper had been the one to accidentally set off the alarm with the initial incorrect password, and by the time he had the right one, the door had been open a few moments when Ford caught them.

Seeing the scrambled code as at least twice as long as the last one, Dipper sighed and followed his Grunkle up into the elevator. He’d probably be able to crack the code again, but it would take at least a few more weeks to get the combination right.

Mabel just smiled, silently thanked Stan for some of the more “entrepreneurial” tricks he had taught her, and slid the object in her sweater sleeve into one hand, and from there to safety in a jeans pocket.

 

* * *

 

“Mabel?” Dipper called up again; the Grunkles had been gone for almost an hour, the first of many. From what Stan had mentioned in passing, they were going to a support meeting for Ford first, and then off for drinks and bowling the rest of the night. In either case, it was an ideal night for some naughty smooching with his favorite and only sister…

…that is, if he could find her.

“Mabes? Where are you?”

There was a groan from upstairs, and in a moment Dipper was racing up the stairs. He heard an “eep!” of surprise, and the attic door clicked shut and locked. He jimmied it, worry overcoming the slight nudge of anticipatory libido from earlier, but it was firmly shut.

“Mabel? Mabel, are you ok? What happened?”

“Um…” came the reply. It was a long and pregnant ‘um,’ and did little to assuage most of Dipper’s fears. After a minute, he prompted again.

“‘Um’ _what,_ Mabes?”

“Um, you know how Grunkle Ford said I shouldn’t have touched those vials?”

Already Dipper had his face in a hand, and he groaned. After a moment, he said “So…are you ok?”

“Yes?” The questioning tone had a hint of confusion and…excitement? Dipper heard the door click, and slowly open. He stepped inside, and saw his twin give him a shy smile, her ears and tail flicking as she saw his-

_Wait, back up a second. Ears and a tail?_

Mabel’s normally downy hair on her arms and legs had darkened slightly, from clear to a hue almost matching her hair. There were a pair of pointed brown ears of a similar color poking out from under the curly hair, and a three-foot bottlebrush tail swooshed around and gently being held in one hand. She grinned, and he could see the faint glint of what must have been whiskers and slightly-longer-than-normal canines in her smile, braces still firmly attached.

“Uh, so I’m guessing that was a, uh, extract of-”

“Cat. Boy genius, everyone,” she said in a flat tone, raising her arms as if announcing to an unknown and poorly-amused crowd. “First he solves the mystery of what his sister turned into, next the cure for aging. Behold-ow!”

Dipper had punched her lightly in the arm, and she batted back his hand. In the process, an errant elbow struck her day-old glass of Mabel Juice, left out to help clear some of the more heady fumes before imbibing. The glass tumbled and Mabel spun to catch it. Still, despite the catch, it partially tipped and spilled some of its contents across her sweater and skirt.

She let out a groan of disappointment that had a distinct yowl of unhappiness. “Aw, man. I was excited for Romance Koala tonight,” she said, showing the winking kissy-lipped marsupial now stained by glittered beverage, along with a not-insignificant amount of her newly-downy arms and legs. Acting quickly before the Mabel Juice stain set and began to harden, his sister grabbed a handful of clothes as a change, and made her way towards the shower.

Dipper chuckled, now that the immediate danger appeared to be past, and began to leaf through his journal for a cure for his sister’s condition. It wasn’t the first time that one of them had suffered a bizarre mutation, and except in one painfully memorable case, all of them were fairly quickly and easily reversible.

He nearly ripped a page out of the journal when Mabel came sprinting back into the room, screeching and buck naked. Dipper’s hindbrain immediately took notice, while he forced his mouth to form understandable English words.

“M-M-Mabel? What’s wrong?” She looked at him, and he could already see a pout lip forming.

“Promise not to laugh?”

“Cross my heart.”

She sighed, averting her eyes as she half-mumbled “I got scared by the shower and the running water.”

Just because they had made out before hadn’t prepared his waking brain for his sister in all her glory. Still, the words bisected the rising heat he felt migrating south, and he stifled a _‘snrk’_ of amusement.

Keeping his voice as conversationally neutral as he could, he said “So, what about the mabel Juice then? That stuff is corrosive if left untreated for too long like that.”

His twin huffed. “I know, I know. I’ll…I’ll think of something, ok? Just…no showers.”

Dipper shrugged, and went back to the journal. He had to fight the urge to spend the entire time staring at her naked form as she sat on her blanket. He had almost started to get some real research started when he heart a soft noise, followed a few seconds later by a noise of excitement.

“Hey! Hey, Dipper, lookit me!” He looked, and Mabel had proudly contorted her arm, tongue extended to poke her elbow.

“See? And Mrs. Bulstrode in second grade always said it was impossible! Ha!”

Dipper chuckled, trying to stop his eyes from flicking to her lightly-fuzzed mound and instead focus on her face. “Yeah, who knew? All it took was some dangerous and probably-illegal magical potion.”

Mabel chuckled, and went back to licking the Mabel Juice off of her arms. Dipper’s eyebrow raised, but then with a snort he went back to his research. I guess it makes sense, as a cleaning procedure. A _lthough I hope there’s no weird interaction between the extract potion and her Juice, since that’s definitely not covered in my notes._ Normally it just made her more hyperactive than normal, but the last thing he needed was for her to start hacking up hairballs all over the attic.

He had just flipped past an unfruitful entry into “The Mushrooms of Millicent Grove, and their Applications” when he happened to glance up at Mabel. His mouth dropped open, as Mabel’s head was tucked all the way down to her thigh, cleaning off the Mabel Juice effortlessly despite it being a feat that should have been impossible with all her ribs intact.

_Is she going to…no, there’s no way she-_

He swallowed, as he saw her head shift to directly between her legs. There was more of the soft noise, and then a notable change in tone. Her breathing became more audible, and as Dipper watched, he could feel his cock straining against his pants as he saw her toes clench and curl slightly with her own self-ministrations.

Then there was a deep breath, a little almost-silent whimper, and he saw her tail flick over her shoulder, tensing along with the rest of her body, before she abruptly sat upright with a smile.

Dipper quickly tried to bury his face back in his book, but he heard an amused purr from Mabel.

“Oh, I forgot I had an _audience,_ ” she murmured. Dipper shot his eyes over the top of the journal, giving her a thin guilty smile, before trying and failing to continue reading the same page for the tenth time.

Then Dipper felt her approach, and she gently pushed his chair backwards, to sit firmly on his leg, still beautifully naked.

Dipper swallowed, feeling as she ran her hand over his shoulder and down his chest, gently raking him through the shirt with her slightly-curved nails. In a low, breathy whisper against his neck and ear, she said “So, I think the Mabel Juice might have had a _slight_ effect, Dip.”

He let out a little murmured moan of approval, before clearing his throat and stammering out “O-oh? What-what effect?”

She ran her other hand down his arm, taking his wrist and slowly guiding it to her shoulder right above the curve of her fuzzy breast. With another murmuring voice, this time underpinned by a groan of pure lust, she said “Well, brother, I think it might have kickstarted me into…well…”

She leaned close to his ear, and at the same time as her hand reached down and pressed against the hardness in his khakis, she breathed out _“I think I’m in heat.”_

Dipper’s brain barely had time to process, before she had met him for a brief kiss. He felt her rough tongue play over his lips, before she broke the kiss, trailing kisses down his chest as she pushed his shirt aside. Dipper quickly removed it, unfastening his belt as she pawed at his waist, and then she unzipped his fly and revealed his shaft.

He took a halting breath and groaned as she wrapped her bare hand around it, dipping her head down to take him into her mouth. She sucked, gently running her tongue along the edges as her hands worked to help pull his pants all the way off and toss them into a corner of the attic.

Then Mabel broke the kiss, leaning backwards on her knees on the floor and grinning at Dipper. Saying nothing except a humming, happy purr, she went back to sit on the bed. Reaching her arms over her legs, she leaned forward, parting her lips and giving them a long and languorous lick before smiling and crooking a finger at her brother.

The other twin stumbled to his feet, coming over to the bed and meeting Mabel’s mouth in a hungry kiss. She hummed approval, but her hands were grasping, finally finding his cock and gently tugging it towards her damp and eager slit. Dipper broke the kiss, giving a little playful growl that sent his sister into a fit of giggles, before pressing his hips forward and sinking into her warmth.

Mabel yowled, groaning in pleasure as Dipper pulled back slightly, and plunged in again. Her nails scratched along his back, before gripping his hips to pull herself deeper onto his shaft. She whimpered, biting her lip and drawing a bead of blood as he pumped against her.

Dipper had an idea then, and pulled out, eliciting another disapproving moan from his sister along with a pouty lip. He just grinned, and murmured “Turn onto your hands and knees, so we can try, uh-”

“-Kittystyle?” Mabel said as she completed the thought.

Both twins snickered, but then Mabel obliged, flipping over. Her tail briefly batted Dipper in the face, curling along his arm as he attempted to move it to one side. After he had nudged it to the side, Dipper gently grabbed her hips, and pulled her to rub against him. His cock slid over her slit, teasingly, before she protested. Parting her lips with one hand, he pressed his cock into her, and Mabel arched her back up as she felt him fill her.

She was whimpering faster and faster now, and Dipper could feel a rising surge at the base of his shaft. He pulled her upright, grabbing her soft breasts from behind as he whispered in her pointed ear “Are you ready for me to cum, Mabes?”

Her reply was a low animal growl of pleasure, and she wiggled her hips on his shaft. Dipper clenched, leveraging Mabel as best as he could to sit deep on his cock as it twitched, and then surged, filling her with surges of wet heat.

His twin’s entire body shook as he twitched and grunted, and her voice was temporarily silent as her mouth was open letting out little wordless squeaks. Finally the voice was restored, and the squeaks dropped into a satisfied growling moan as she gave one last wiggle on his shaft.

“Mabes, even as a catgirl, I love-”

**BAM!**

The sound of the front door of the Shack banging open surprised both twins into frozen silence. They could hear a distant voice muttering angrily “-but who the hell closes a bowling alley? On a Saturday? I tell you-”

Then there was a sharp sneeze, a cute little noise that Mabel would have thought came from Dipper if he hadn’t already been next to her. This was followed by a trio more of the same-pitched sneezes, and then Grunkle Stan’s voice:

“Aw, you still sneeze like a kitten, Sixer. Speaking of which, though, I haven’t owned a cat since my flat in Reno. What could be-”

Another set of sneezes interrupted him, followed by a very angry and phlegmy roar from Ford.

“DIPPER. MABEL. DOWNSTAIRS, NOW!”

**Notes for the Chapter:**

> Prompt from an Anon: Because of some new Gravity Falls weirdness Mabel has been turned into a catgirl. Which has left her with not only cat ears and tail, but also extreme flexibility and some new instincts. As Dipper tries to find a way to change her back Mabel starts cleaning herself with her tongue, eventually going down on herself, much to Dipper’s distraction.


	3. Special Discount

Dipper hadn’t thought much of it when Mabel had ducked below the level of the counter. There was only one elderly man shopping in a corner, mumbling something to themselves, and other than that, the Mystery Shack gift shop was empty as could be. She was bumping around with something, before moving a jar of something suspended in formaldehyde to the counter with a clunk.

As she pulled her head back, her head bumped his crotch, and the half-boner Dipper had been sporting all afternoon roared to sudden life. Mabel’s sweater was especially diaphanous and form-fitting today, and she had teased him when she had slipped into it that morning. It had been on his mind all afternoon, causing him numerous distractions and nearly dropping a snowglobe of a stylized Weirdpocalypse when she had stretched earlier.

He glanced down, and swallowed hard when Mabel looked back with a hungry grin on her face. She gave him a saucy wink, and Dipper abruptly scooted to the side to put his torso and waist in line with the bulky and outdated cash register, concealing himself as Mabel unzipped his fly and carefully drew out his shaft.

Both twins froze, staring in the direction of the only customer as he let out an especially loud hacking cough, and then Mabel broke into a nearly-silent giggle as Dipper coughed, cleared his throat, and grinned awkwardly.

His sister began stroking his shaft, pumping it slowly with one hand while her other reached up to roam beneath his shirt and up his back, gently dragging her nails across his goosebumped skin. Dipper shivered, and let out a breathy moan, and saw Mabel smile at him again.

Then his twin leaned forward, and he had to lean on the counter for support as Mabel took him into her mouth. She ran her tongue along the edge, humming and causing a wonderful vibration in the process as she lazily moved her head back and forth along his hardness. One of Dipper’s hands reached down, running through her brown locks, and her happy hum increased, causing him to shiver again as his knees threatened to buckle.

Then she began to bob her head faster, the gently teasing tongue giving way to harder sucking, running all around his shaft as he felt her hot breath, deep and quick with effort as she closed her eyes to focus on the pleasure. One of her hands had ventured into her pants, and the other had dipped under her sweater. In the afternoon light, Dipper could make out the faint pinkness of a barely-visible breast, freed from a lacy bra and being teased by her own hand as she-

“Oh sonny?”

Dipper let out an “Eep!” of surprise, and also of pain as Mabel accidentally engaged some teeth as he felt rather than heard a muffled “Mmp!” of surprise from around his cock. He shot upright, or at least as much as he could with Mabel’s mouth still wrapped around him, only to see the old man carrying some gaudy t-shirt. He was standing a few feet back from the register, and given the fact he wasn’t screaming for the police, he must not have seen Dipper’s sister in mid-blowjob.

He almost started to relax, when he felt his twin’s mischievous grin around his cock. The sucking continued, slowly, but then with full vigor. Mabel was breathing as quietly as she could, and Dipper doubted anyone but him could hear her over the hum of the little fan on the countertop, added to try to fight off the heat wave.

“Y-Yessir? What c-can I do for y-y-you?” The stammering was as best as Dipper could do to speak normally at the moment, as he shivered again from Mabel’s vigorous sucking.

“Oh, I just wanted to get this shirt for my grandson.” The older gentleman cocked his ill-kempt hair. “Sonny, are you ok? You look like you’re in pain.”

Dipper struggled to keep from snickering along with the silent snickers he felt vibrating on his shaft, and instead he had a flash of insight.

“It’s…it’s my sister, sir.”

He felt Mabel’s mouth pause, and he could picture the confusion on her face without glancing down.

“Oh?” The man’s face became a mask of sympathy. “I know how hard it can be to lose someone close.”

Dipper nodded as solemnly as he could, all while feeling the surprisingly-arousing rumbled of Mabel’s mute laughter on his cock. She had begun to suck again, and Dipper decided to go for broke as he felt the surge rising at the base of his shaft.

“Sometimes,” he said in a mournful and low voice “I can…almost feel her, as if she’s right next to me.”

The customer had nodded, eyes brimming with tears, and abruptly Dipper had to convert the groan of orgasm into a groan of fake pain, as Mabel’s giggling sent him over the edge and into pulsing cum into her mouth. She sucked him dry as best as she could, but the giggling was only slowed. As he felt her break the connection with uncontrolled and imminent laughter, Dipper moved from moans of agony into wracking put-upon sobs, loud enough to drown out his sister.

Luckily, between the fan and the fake sobs, Mabel’s quick laughter was stifled before the old customer noticed anything amiss. He just nodded, head bowed, and met Dipper’s gaze with wet eyes.

“Well, stay strong, sonny boy. Sometimes feeling them close is enough, and helps put our troubles incest.”

Dipper’s eyes widened, and he stammered out “W-what?”

The old man cocked his head, his sadness turning to puzzlement. “I just said that feeling sad about them helps put your troubles at rest. Sonny boyo, what did you think I said?”

Dipper coughed and shrugged, and quickly rang up the purchase. The old man paid and left, and then Dipper turned to look at Mabel. There were white spots on the edge of her mouth where laughter had worked against tidiness, and she wiped them clean with a slender finger, popping it in her mouth and smiling as she winked at Dipper.

“Well, brobro, I think that was a success. Are-”

The door to the Shack gift shop nearly banged off the hinges as Grunkle Stan slammed it open, leading in a flood of almost a dozen new customers. He looked over at Dipper, flaccid cock hidden behind the trusty cash register, and just grunted “Take care of the customer, kid. Milk ‘em dry, you know the drill.” Then he slammed the door shut, and was off to parts unknown again.

Mabel glanced upwards, running a finger along his shaft as it gave an appreciative and responsive twitch. In a voice loud enough that only Dipper could hear, she murmured “Are you ready for round two?”

**Notes for the Chapter:**

> Prompt from an Anon: Mabel pleasures Dipper behind the counter at the Mystery Shack while he helps customers.


	4. The Pact

“Wait, so you’re telling me-”

Pacifica nodded, her normal flat expression replaced with a glin of mischievous glee. She and Mabel were sitting in the Northwest’s bedroom, her parents off in another part of the mansion to scrutinize some paperwork or other.

“Yup. I use it as my way to, heh, ‘relax’, after a long day. For a small town, that gloryhole gets a surprising amount of traffic, and some of those bikers are…whoo, are _very_ nice, if you know what I mean.”

Mabel gave her a look of both amazement and slight respect as Pacifica fanned her suddenly-flush face. She sat up, deep in thought at a sudden idea. She waved her hand in front of Pacifica’s face, to get her attention from her reverie.

“So, Paxy, um, you know how you’ve, well-”

Pacifica sat up, her face shifting to annoyance; she had inherited just as short of an attention span as her parents. “Yes yes, spit it out already.”

“Well, you’ve wanted to jump Dip’s bone ever since I told you I was jumping his?”

That was patently _not_ what Pacifica had expected Mabel to say, and she coughed, the slight flush from earlier returning with a vengeance. She took a breath through her nose, and squeaked out a little “Uh, yes? You could say that?”

This time, it was Mabel’s turn to give her friend a wicked smile.

“Well, let’s just say I have a trade in mind. Interested?”

Pacifica just nodded, and Mabel leaned over and began whispering into her ear.

 

* * *

 

“Mabel, this-this is both an awesome and terrifying idea. Did I say that already?”

Mabel rolled her eyes as Dipper stared out at the biker bar they had parked across from. He coughed, tugging slightly at the most “rough” outfit he could assemble on short notice. It was a white shirt, some jeans Mabel had told him he looked sexy in, and an old leather vest he had borrowed from Grunkle Stan’s study.

“Yes, Dipper, you mentioned that already. Heck, if we’re gonna do fun naughty roleplay at home, why not do it here? Besides, nobody’ll recognize us.”

She was lying, but she knew her twin would accept that lie more than he would the truth: at a bar like that, nobody gave two shits about what you did so long as it wasn’t bothering the other patrons. In any case, his hat was sitting on the bed at home, replaced by a blue bandanna around his head and over his birthmark. Mabel had curled her hair, far more than the natural slight twist they had at the ends; as for her clothes-

“So, uh, do I get to see what’s under the coat, or…?” He left the question hanging, trying to keep out the eager curiosity out of his voice.

 _I swear, I could get him to walk off a cliff if I told him there was a mystery at the bottom of it. Heh, well, probably time to stop teasing the fire, and let that sucker burn._ She gave him a full smile from behind her shades, keeping them on as she stood and exited the car. As Dipper followed suit and stooped to get out, he could hear a rustle of fabric. Looking back, the coat had been flung into the car and the door slammed behind it. Mabel was standing in a thigh-length pleated leather skirt, her top a silk brocade halter top, tied with just a thin string in the back, hugging her ample form and clearly showing off the lack of bra. Meanwhile, the slit in the side of the skirt made it clear that if she was wearing anything underneath the leather, it was minimal indeed.

Dipper swallowed, and Mabel savored the effect, striding in on clicking heels, ones Dipper could see wrapped around in sandal-style straps halfway up to her knee. The remaining effect was some thigh-high fishnets, leaving a thin strip of bare flesh between the end of the skirt and the start of the fishnet, and a SmileDip lollipop between ruby-red lipsticked lips.

“Well, brobro? You seem a bit parched. Why not join me for a drink in a minute?” Then she spun, privately enjoying the way Dipper’s eyes roved across her form before she strode away, stepping through the door. Dipper hung behind, taking a deep breath to try and control his libido and let his analytical mind remind him of the plan; wait a few minutes, come in, order a drink separately at the bar so it didn’t seem like they were together, and then follow her into the restroom, where the fabled gloryhole awaited.

Still, Dipper was a bit surprised. I _know she said she had borrowed some of Paxy’s clothes, but I remember Pacifica had said that top and skirt were some of her favorites, and off-limits for sharing. She’s pretty picky about who gets to use her heels too, if I recall right._

He shrugged, and as the silent countdown expired, began to follow Mabel inside. _Well, I’m sure whatever sweater or something she traded Pacifica for, it was worth it._

As he entered, he paid little heed to the rest of the bar. The other patrons barely glanced at him, and he likewise avoided staring at any of them. Mabel’s bare back was visible sitting at one end of the bar, and he markedly sat at the other. He saw a few patrons had shot glances at her before returning to their drinks, and he ordered a glass of hard cider as he avoided staring at his sister. He saw her glance his way from under the shades, before returning to her drink; something multicolored, with an umbrella in it. The umbrella looked tattered and previously used, but Mabel didn’t mind, stretching back to take a sip.

The minutes ticked on, and Dipper’s cider was mostly-drained by the time Mabel finally shifted. Slapping a few bills on the counter, she hopped off of her seat, landing on the worn wooden floor with another clack of her heels. Not glancing back, she strode off towards the restrooms, and after a long count to one hundred, Dipper finished his drink, paid his tab, and followed her in that direction. Sure enough, just as Mabel had reassured him earlier, no-one so much as glanced at him following her, and he let out a little private sigh of relief as he passed through into the hallway.

As Dipper left the bar, another patron stood, from a corner near the door. Mabel had only glanced for a second at the aptron, and inclined her head, and as planned, Dipper ignored the corner entirely in his effort to avoid catching the gaze and ire of one of the bikers saturating the bar. This patron shrugged off her coat, leaving a single overlarge golden coin to pay for her drink as well as some privacy; the bartender just nodded by way of acknowledgement, pulling a little chain across the hallway entrance with a little sign that read _“PISS OFF AND PISS ELSEWHERE.”_

This patron had a pleated skirt, this one with a deep cherry red hue to the leather, and a silk brocade halter of navy blue and pearl white, rather than the black and pinks and reds of the design on the halter Mabel had borrowed. Pacifica took off her glasses, smiling with nervous anticipation as she saw the _Occupied_ on the men’s restroom, and gently knocked the signal on the _Occupied_ ladies room. The door cracked open, Mabel saw her, her grin visible even through the crack in the door, and she pulled her through before snapping the door shut behind her.

Pacifica’s heart was racing. _I’ve done this a dozen times before, with strangers I’ve never seen the faces of, so why the hell does the thought of Dipper’s cock being the one make me feel-oh, oh my god-_

Her train of thought broke off as a mostly-rigid cock poked through the hole in the wall. She looked at the pink shaft, the slightly-darker head and slight dusting of hair near the base, and a tiny glint of precum from anticipation. Mabel ducked her head close to Pacifica’s whispering _“Remember: First suck is mine, and then he’s all yours for the first round.”_

Pacifica nodded, and Mabel grinned, then moved over to her brother’s cock. She gripped it gently at the base, and Pacifica saw it twitch, before she leaned in and gave a single lazy lick around the head. There was another twitch of excitement, and she ducked farther down on it, sucking his shaft in deeper with a hum Pacifica could hear and appreciate. She felt a dampness between her thighs, and let a finger run down there to rub gently as she watched Mabel suck her twin’s cock. However, as Mabel’s sucking increased in speed, Pacifica felt a twinge of lust and frustration, and she stared pointedly at Mabel. The Pines twin cracked her eye open, saw the gaze, and smiled and shrugged, her mouth still occupied. Then she broke the suck with a gasp, and in a single stride made her way to Pacifica.

Before the Northwest heir could say anything, she had her mouth filled with a hot, breathy kiss, and Mabel hummed. Pacifica could taste a slight saltiness to the kiss, no doubt from Dipper’s cock, and she felt as Mabel’s hand dove beneath her skirt, catching her own and joining it to rub along her eager slit, feeling the moist heat through the silk thong.

Pacifica hummed, but then Mabel broke the kiss, stepping back with a smile, and then a nod towards her brother’s awaiting shaft. Pacifica nodded, biting her lip slightly, and she approached, gently grasping Dipper’s cock near the base, as she had seen Mabel do before. She felt his hard heat, felt him twitch eagerly, and then she ducked down, kissing the tip gently, before slipping it into her mouth.

She felt the taste, warm and already moist and faintly sweet from Mabel’s mouth before hers. She hummed, breathing out and inhaling his musk deeply, swirling her tongue around his shaft. He twitched, and she could hear a faint groan of pleasure from the other side of the wall; she hummed again in pleasure, running a hand under her panties as she rubbed along her length, feeling her own heat build as she sucked on Dipper’s shaft, until she let out a muffled cry, her legs clenching with a small spasm. She felt Dipper’s cock pulse, and awaited, ready to swallow his cum, but none came.

While part of her was disappointed, the rest was excessively pleased; many of the bikers had the stamina of a bottle rocket, and she was in no mood to hand over control to Mabel yet. She gently let Dipper’s cock go with a final swirl, but then kept pumping the shaft as she stood. She ran a finger along the slit, turning to face her ass towards the hole, and in doing so she caught sight of Mabel. The Pines twin was staring at her, panting, with the brocade shoved up to expose both breasts. She was massaging one, adn the other hand was mastrubating furiously under the skirt, the faint sounds of her rubbing and breathing turning Pacifica on even more than she had already been.

Mabel nodded, her face filled with pure and unfiltered lust, slightly open as she panted for breath, and Pacifica shimmied backwards, until Dipper’s cock was between her legs. She let him rub along her wet slit, feeling the appreciative jolt of renewed interest, and then angled him to slide into her, filling her with his shaft.

Pacifica let out a faint gasp of pleasure, and gasped again as Dipper began fucking her through the wall, pumping as best as he could given the limited space. She felt his thrusts, and the angle was hitting all the right spots as she felt a twinge building already. She gripped the handrails, pulling Dipper deeper into her as she grunted and felt herself spasm on his cock. He continued to pump, and the rigidity in her back melted as abruptly as it came, slumping forward to feel his cock still ramming into her. She could feel smaller spasms, miniature orgasms following the first, and she panted, squeaking and trying not to cry aloud with each of them as she felt his cock begin to shake.

_Holy shit, Mabel wasn’t kidding when she said Dipper had endurance to spare. Two blowjobs and at least three orgasms on my end is two orgasms more than that one biker with the tattoos and the piercing last week._

Finally, Dipper gave a low moan from his side of the wall, and his cock exploded, pulsing heat into her, filling her as she felt her legs clench, a muted squeak building. Just as she felt her lips about to break free and cry out, Mabel’s mouth was on hers, her heat muffling her scream of pleasure as she felt Dipper’s seed spill out, slowly dripping along the interior of her thigh. She took a staggered step forward, and slowly sank to sit on the toilet seat, legs shaking.

Mabel took her position, quickly catching the last pulse of Dipper’s cock in her mouth, swallowing and licking him clean as she gently pumped him. Pacifica sat, smiling, her mouth hanging open as she panted, and she reached over to help. There was a jolt of surprise from Dipper as he felt more hands on him than one sister could provide, but he said nothing. Mabel leaned over to give him little kisses, trying to renew the energy of ‘Little Dipper’ as fast as possible, when there was a faint rapping from the panel of wood covering the gloryhole on the _other_ side of the stall.

_Oh, right. A bunch of bikers just saw two hot women wearing clothing that would make a hooker blush enter the one bathroom in Gravity Falls with gloryholes. So much for ‘privacy’. Shit, I’m surprised this didn’t happen earlier._

She tapped Mabel on the shoulder, and upon seeing her questioning glance, pointed a thumb at the other gloryhole’s covering panel. Mabel’s head cocked in confusion, then delighted surprise, temporary deep thought, and then a smile and nod, one filled with a visibly-building lust.

Pacifica unlatched and removed the panel, and barely a second later a veiny cock protruded through. It was about twice as large around as Dipper’s, and Pacifica wanted to let her pussy rest for a minute before filling it again. Instead, she leaned over, and took the cock in her mouth, sucking vigorously, occasionally running a tongue and around to suck on the balls that had been proffered through as well.

As she sucked and pumped, she could feel the heat between her own legs returning and eager for another cock, but before she could stand the cock pulsed in her mouth. She began swallowing, feeling the ropes of cum bitter on her tongue as she gulped them down, sucking the lucky cock dry as the twitches faded, and the flaccid shaft began to rapidly shrink.

On a whim, Pacifica turned to Mabel, who was still stroking her brother’s slowly-strengthening shaft. She kissed her on the mouth, plunging a tongue through to meet Mabel’s, and feeling her surprise, and then hum of excitement as she tasted the lingering cum. Mabel broke the kiss, muttering with a giggle “You’ve got another customer.”

Pacifica turned, seeing this time a slightly-darker shaft poking through. This cock wasn’t as veiny as the first, but was slightly longer. Feeling the heat along her slit building, Pacifica turned to press her ass up against the wall, running the biker’s cock along her sticky and cum-covered slit. There was a grunt, and then the cock pulled back slightly.

Worried, Pacifica began to turn to see what was the matter when the shaft plunged forward, piercing into her as she gasped. Her eyes were clenched in surprise, but then popped open as the biker began pumping vigorously. She squeaked, feeling another orgasm build far faster than she had anticipated, and she looked up to see Mabel sighing and groaning as Dipper’s cock pressed into her. Mabel’s eyes cracked open and she reached out one hand towards Pacifica. The stall was small enough that their faces were almost touching, and Pacifica stretched out slightly in the hopes that Mabel would do the same.

She did, and met Pacifica’s mouth with a hum of erotic approval, her tongue running across Mabel’s flavored lip gloss as she felt her slight huffs of breath with each of Dipper’s thrusts. Pacifica, for her part, was panting continuously with the jackhammer pace of the biker who was drilling her, when he felt her slow, and withdraw.

Puzzled, she stayed where she was, and felt his cock return, moistened on the tip as he pressed it gently at her tight asshole.

_Well, I wasn’t planning on this, but might as well give it a-FUCK!_

The biker must have taken her stillness as agreement, and pressed into her ass. She squeaked with surprise, then a moment of discomfort, before the head poked through and she felt his cock filling her again. The sensation was different but not at all undesirable, and Pacifica, grunted with excitement as he began to pump, slowly at first and then quickly resuming his previous speed.

Mabel had watched the change of orifice with a look of confusion, then concern, then a bit of jealousy, but then she squinted her eyes shut and began to pant. Pacifica could see how the pumping became faster and the strokes deeper, and could tell Dipper was about to cum, in his sister this time.

Pacifica pulled Mabel forward, meeting her in a kiss as her hand reached below, rubbing along the Pine’s chest and into her soaked panties before rubbing along the nub of her clit. She could feel Dipper’s thrusting, but her gentle rubbing had Mabel panting against her mouth, eyes half-closed in ecstasy. Mabel reached forward and began to do the same for Pacifica, and she could feel the biker’s cock finally twitch,a dn then begin pumping cum into her ass, filling her with the warmth before quickly withdrawing.

Pacifica fell forward onto her knees, and as she felt her own orgasm begin to shudder and crash through her, she leaned up, sucking Mabel’s nipple into her mouth. Mabel cried out, gasping a tense “ _Yesyesyesohhhhhh!”_ as she clenched and shuddered on Dipper’s cock. Dipper’s groan was much louder this time, and soon Pacifica could see a faint dribble of white touch the dark lace upper edge of Mabel’s borrowed fishnets.

Then Mabel dismounted Dipper’s cock, falling forward onto her knees, to reach for Pacifica’s face, smothering her with little hot kisses, along her mouth, and cheek, before reaching her breast and giving it a reciprocating suck as well. Pacifica groaned, feeling one last shudder twitch her legs and crotch, before she opened her eyes to see Mabel staring back at her.

Dipper’s voice came through the hole, as he said “So, uh, ‘stranger,’ who was the friend you-”

Mabel giggled, closing both holes with their respective panels, as she said “Hush. We need to get-” -she shot a mischevious look at Pacifica- “-cleaned up.”

Before Pacifica could say anything, Mabel had lifted her bodily up against the wall, resting her legs on the Pines twin’s shoulders, and the Northwest girl sighed as she felt Mabel’s tongue begin sliding along her slit, darting in and around as it lapped up the remainder of her brother’s cum. She could feel herself twitch, clench, and a little cum leak out of her ass as she came again, letting out a shriek she tried to half-mule with her hand, before forcing Mabel off of her with a shuddering laugh.

Then, with a slender fishnet-gloved hand, she pushed Mabel to lean backwards on the toilet, and ducked down to lift and hold back the leather skirt. She began trailing kisses down, around Mabel’s trimmed bush, along either sticky thigh, before finally reaching the center of her. Running a tongue lazily along the edges, she appreciated Mabel’s gasping hum of approval, before ducking her head in and thrusting her tongue into her slit, loving the hot taste of Dipper’s cum, still fresh from filling his sister.

She ran her tongue along, alternately teasing and venturing within, until Mabel began to squeak, her thighs clamping to either side of Pacifica’s head as she groaned and gasped. Then she released, allowing Pacifica to cough and catch her breath, smiling at Mabel as she gasped and gave her a demure grin.

Mabel got to her feet, unsteadily at first, before unlocking it and slipping out. The door was shut behind her, and Pacifica stood, slowly and also shakily on weakened legs, as she heard Dipper’s voice, low and raspy.

“Holy _fuck,_ M-miss. Do I get to meet your friend?”

Mabel’s reply was equally low and lusty. “I don’t know. That’s up to her.”

Pacifica sat there, thinking for a moment, before sliding the latch shut again to read _“Occupied”._ Mabel laughed from outside.

“I guess not, br-uh, buddy. Care to, heh, drive me home?”

“All right then, I guess I’ll meet her next time. “ Pacifica’s body let out a little twinge of excitement at the idea of a next time. “Follow me, _miss.”_

As she sat back on the toilet and collected her thoughts, enjoying the warm and sticky heat still filling her, Pacifica heard a knock on one of the cloryhole panels, and then a few seconds later a knock from the other.

 _Well, the evening’s not over yet_ , she thought, unlatching both and grasping the cocks that emerged, hot and hard and full of anticipation.

**Notes for the Chapter:**

> Prompt from an Anon: Mabel discovers gloryholes and convinces Dipper to try one with her. Mabel and Pacifica make a deal and Dipper ends up doing Paz.


	5. Ratatouille

Dipper ran to catch up with Mabel as she practically sprinted towards the grocery store. He turned, a last-minute mental reminder nudging him to lock the van they’d rented with the keyfob, before turning to jog and catch up with his sister. The Stanley Mobile was in the shop, again; Grunkle Ford had mentioned something about accidentally running over a leprechaun and the damage the pot of gold did to the radiator, before shooing the twins out with a stack of money to rent a temporary vehicle.

Dipper, for the most part, had been distracted since they got in the car. Grunkle Ford was in his lab, Grunkle Stan was fleecing tourists, and so nobody noticed when Mabel came running out after a brief change of clothes.

Nobody, that is, except for Dipper, who had to avoid staring too much as he saw Mabel had swapped into the pleated black leather skirt she had borrowed from Pacifica a few weeks back. Her sweater had been changed to a shiny glittering red, with a flaming chili pepper on the front and backed by three-inch gold letters spelling _SPICY_ embroidered in.Even the socks were a change, from her normal short ankle-length ones to ones that came just over her knee, white with a red stripe, and helping draw attention to the dark and supple skirt in the process.

She was giggling, and going on and on about the recipe she had wanted, which had confused Dipper to no end. Normally Mabel was all about Mexican and Japanese dishes; if someone had invented burrito sashimi, or made a seaweed wrap filled with smoked salmon, cream cheese, and avocado, she would have been in pure blissful heaven.

But Italian food, on the other hand…

“Mabel, why ratatouille? I know there was that film with the mouse and all, but it’s not like you to up and cook some pasta when tortillas and tuna filets are freely available.”

He was leaning back against a display of apples, as Mabel practically pranced around with the shopping basket. The store was almost empty, the faint sound of a squeaky wheel several aisles away and the somnolent beeping of a checker on the other end of the store the only sounds this late at night.

Mabel turned, a know-it-all-smirk as she told Dipper “Actually, ratatouille has no pasta in it, and instead relies on an eggplant and tomato reduction sauce, drizzled over a bed of soft-coooooooked-”

She drew out the word as she rummaged for something, and then spun, her smirk replaced with a saucy smile.

_“Zucchinis!”_

Dipper stared, nonplussed, at the long and lumpy vegetables she thrust forward to show him. Then his eyes drifted from the vegetables to his sister’s face, and back again, before returning to look at her with a raised eyebrow.

 _“Really,_ Mabel?” His voice dropped to a murmur. “You have, like, a literal carry-on backpack filled with toys. I saw it! There’s that pink one, and the purple ridged glittery one, and the one with the suction cup and the remote-”

Mabel silenced him with an upturned finger gently pressed to his lips, before stepping back to lean against an orange display.

“While true, brobro, I don’t have them _here_ right now. What I _do_ have is, well…”

She smiled, lifting the front edge of the leather slightly with the green squash, revealing a pair of pink lips, exposed to the world in the fluorescent light above. Dipper swallowed, feeling his pants begin to strain and tighten.

_Okay, so while it’s not like we haven’t had sex while she was wearing this very skirt, this is, ah, waaaay more public than I had-_

His train of thought hit a bump, as she ran the tip of the zucchini’s shaft along her lips. Dipper could see the mottled green flesh take on a sheen, as her excitement rubbed off on the squash, and she began breathing even more heavily, as her other hand began to creep up under her sweater.

“Well, Dipper? Like what you see?” She grinned, letting out a little gasp as she pressed the vegetable up against her exposed slit. The orange stand gave a slight creak of protest as more of her weight leaned against it, and in a murmur she said “Dip, I’m imagining this is your cock, rubbing up, ah, rubbing up against me, wanting to press inside me and fill me with your hardness.”

Dipper swallowed again, and more than a little of his brain was shouting to bend Mabel over the clementines and fuck her brains out. The majority of it, however, was petrified at their current location, and in a little breathy gasp, he squeaked “Mabel, not that I don’t appreciate this, but we’re in a store. Someone could be by any minute, and-”

Mabel waggled a finger at him, rolling her eyes. “Oh, Dipper. The old guy on the fourth aisle is slow and miles away, and apart from him and the checker, the store is all ours.” She punctuated the thought with another gasp, and Dipper could see she was running the tip along the edge of her lips, her legs occasionally quivering as they reached an especially wonderful spot. Dipper had unconsciously reached out for support as he felt his cock throbbing against his jeans, and bruised an apple as his white-knuckle grip clenched with his own groan of appreciation at seeing his sister doing this, here, just for him.

_Well, while someone could be by any minute, they probably won’t be. Besides, Mabel doesn’t look like she wants to be interrupted._

She let out a hiss of pleasure, and Dipper felt his cock surge and throb as she began inserting the zucchini into her. There was another little gasp, as she giggled and whispered “Oh, it’s _cold!”_ Then the giggling dissolved into another gasping moan, and her knees bent as she worked the squash into her pussy. Her free hand had nudged her sweater up and over a bra-free breast, revealing a peaking nipple in the chill breeze of the produce section.

Dipper licked his lips, growling a low groan of lust, and Mabel hummed and moaned in reply. She began to work the zucchini in and out of her, slowly at first, twisting and enjoying the sensation of the ridges and bumps, the irregular pattern teasing and nudging her in just the right ways when she wasn’t expecting it, and she already felt a small climax build.

She let it wash over her, her legs twitching, a faint drip of excited heat running over her fingers and down the length of the vegetable’s shaft. Dipper’s eyes followed it the whole way, as he felt a deep and tangible pang of jealousy for the squash. He reached down, one hand going to his fly, but as he reached the zipper, Mabel’s eyes cracked open from their reverie, and she tutted at him.

“Not yet, Dip. This time it’s all look, no touch.” She gave him a wink. “No touching for you, at least.”

Her free hand tweaked and teased her nipple, and it began trailing down her chest and towards the uplifted skirt.

“Me, on the other hand, I can touch as much-” The fingers reached the end of the zucchini “-as I-” they trailed upwards to her trimmed mound _“-want.”_

Her fingers began working around the squash, and Dipper could see them dipping right over her clit as she gasped and a leg shook in a spasm of ecstasy. Her thrusting of the zucchini started going faster, and faster, her breathing faster and lighter as her eyes peeked open for a moment to look at her twin.

Dipper was gripping the apple stand for dear life, his cock painful as it sought to break free of the confines of his pants, and his breathing was shallow, underpinned by a panting growl that made Mabel feel shivers along her spine to hear it. He grinned as he saw Mabel’s gaze, and she squeezed her eyes shut again, feeling his eyes still on her as the thrust the squash into her, feeling the white-hot peak building and building.

In a sudden gasp, she felt the orgasm explode, and she fell to her knees. A moan sprang to her throat, and she managed to keep it low enough that she was fairly sure only Dipper would be able to hear and appreciate. Around her lips, she could feel the surge of damp heat, and a trickle of her natural lube teased its way down the inside of both of her thighs, stopping only upon reaching the tops of her socks.

Dipper was breathing faster and faster, and Mabel took a stumbling few steps forward on her hands and knees until she was right in front of him. He was breathing heavily, and she could tell her brother was on the verge of exploding; she tore at his zipper and the intervening boxers as if she was possessed, and freed his throbbing shaft only to immediately engulf it in her mouth, sucking him deep as she buried her face and inhaled his musk of excitement.

It was just in time, as her twin groaned, one hand cradling her head and interweaving his fingers into her curly hair, the other nearly cracking the wood of the stand he was leaning against as his cock pulsed, and then filled her mouth and throat with a warm saltiness that she swallowed with a gasp through her nose. She continued to suck, swallowing as he shot ropes of cum into her mouth, groaning as she ran a cleaning tongue in little swirling circles around the shaft, still twitching with afterglow.

The squeaking of the old man’s trolley cart a few aisles closer than when they had started broke the reverie, and Dipper gave Mabel a single deep kiss as she got to her feet, then tucked his cock back into the pants.

“Damn, sis. That was cutting it close, but-”

She grinned, leaning against him. “But?”

“But, I can’t say I minded the end result.”

She beamed at him, giving him another peck with her warm mouth, the faint salty tinge of his orgasm still tangible behind her cherry lipgloss.

Then Mabel, turned, starting to walk away, and Dipper called after her. “Uh, Mabes? Aren’t you forgetting something?”

She glanced back, giving Dipper a raised eyebrow, and she glanced at the used zucchini. “Dip, did _you_ want to be the one to take a sticky, body-temp vegetable through the checkout?”

Dipper looked again at the befouled squash, then coughed awkwardly before laughing. “Good point. I guess we should get going?”

She smiled, nodding with a grin. “Yup! Let’s go get burritos at, say, Taco Bell?”

Dipper blanched, and shook his head. _“Ugh,_ no thanks. How about Hermanos Brothers instead?”

Mabel shrugged, and then looped her arm through Dippers as they quick-stepped out the store, past the unsuspecting cashier in the middle of counting a stack of coupons, and then ran, laughing, towards the van.

 

* * *

 

From within the security booth, the green glare of the camera feeds illuminated what looked like a shampoo bottle had been smashed with a sledgehammer on the desk. One particular feed for the produce section had been put to the main screen, although said screen had a smudge of something dripping down one corner of the CRT monitor. The thoroughly-spent young man sitting slouched in the chair panted, catching his breath, before muttering to no-one in particular “Holy _fuck._ Cleanup on aisle, on aisle…whatever the fuck aisle this is, I guess.”

He sat forward, pulling out a cellphone, and as he futilely tried to clean with a wad of paper towels, he listened to the ringing, until a female voice picked up.

“Y’ello? Smabble here.”

“Hey sis? You won’t _believe_ what I just saw…”

**Notes for the Chapter:**

> Prompt from an Anon: Mabel wears a short skirt and no panties, proceeds to tease Dipper in public.


	6. Say It

“Say it.” Mabel’s voice was tight with frustration. “Out loud. Say it!”

The young man with the over-pale skin before her smiled, revealing too-long canines. “You’re a vampire, Mabes. Just like me.”

She shot back, her eyes narrowing. “Oh, no really doofus? Gee, the rash I get in direct sunlight and inability to eat garlic chicken wings along with the _terrible thirsting craving that never ends_ were all _kinda_ clues. Also, don’t ‘Mabes’ me, Eric; we’ve been done for over a week.”

Eric ducked his head, muttering out an apologetic “Sorry” as Mabel huffed. He looked up when she cleared her throat again. “Yeah?”

“I’m _still_ waiting for an answer. Candy managed to sneak me a baggie of blood from the donations she was tallying, something I am deeply indebted to her for, but when I tried drinking it, _no bueno!”_ Her mouth twisted in remembered disgust. “It tasted like someone made a penny-flavored V8.”

Eric coughed, one hand rubbing his neck as he muttered “See, this is part of why I cautioned against this relationship at the start.”

He swallowed as she strode up to him, wagging a finger under his nose as she growled “Eric, I have felt like I was on a Mabel Juice hangover for _three. Fricking. Days._ At this point I would commit whatever act of atrocity was needed in order to make the feeling go away. So cut the bullshit: What, _exactly_ do I need to drink?”

Eric cleared his throat, and with a look of embarrassed defeat, gestured in the general direction of the crotch of his pants. Mabel cocked her head in confusion.

“What, like, drink penis-blood? I mean, I know its all spongy and filled with anatomy and stuff that fills with blood, but I would have thought that blood would have been basically the same no matter where-”

She cut off as Eric stared at her, one hand massaging his forehead.

 _“Ohh.”_ She sat back, nonplussed. “Well, I can’t say I was expecting that.”

She wrinkled her nose, looking her ex-boyfriend up and down again. “So, like, can I at least…y’know…off of you? Like, until I find a new, uh, ‘source’?”

Eric shrugged. “Sorry, no can do. I’ve tried it myself, and if it’s from another vampire, it tastes as filling as water.”

Mabel nodded, brow furrowed. “So I guess I’ll have to-” She shot her head up. “Wait, whattya mean, _other vampires?_ I thought you told me I was your _first,_ asshole!”

Eric suddenly looked like he had been trapped in a corner by a family of angry wolves. “Uh, I uh, well, y’see, after a hundred years it gets sorta hard to-”

“Get _OUT!”_

As the door slammed behind him, Mabel sat back in her dorm room.

_Well crapola. I can’t exactly make a Flamr profile and put “Hi, I’m a vampire, need to suck your cock ASAP” in the tagline. Where in the heck can I get-_

_Oh. Oho._

_That’ll work._

 

* * *

 

Dipper sat forward, as Mabel came in. She had prefaced her entry by asking if she could come in, something that only poked a slight twinge deep in Dipper’s cryptid hindbrain. When she ducked away from his mouth after he had asked her what was happening, following a healthy bite of leftover garlic cheesy bread from the pizza place on campus, the hindbrain began to buzz faster and louder.

It wasn’t until she hissed and fell backwards when he went to move his backpack, and his Flying Spaghetti Monster keychain dangled into view, that everything came together.

“M-Mabes, are you a-?”

She looked at him with a worried look as he swallowed and spit it out.

“Vampire?”

She groaned, looked worried, and flopped back onto the bed. “Yeah. At least, I think so?”  
  
“What do you mean ‘you think so’? Vampirism seems like a pretty yes-or-no thing.”

“Well, you remember Eric?”

“Yeah, your weirdly-pushy boyfriend? I remember at that one party a few months back he kept trying to have me take some shots with the rest of you. Why?”

Mabel groaned a little quiet “ _Wow, that makes more sense in retrospect.”_ She leaned up, grinning to show Dipper her notably pointed and lengthened teeth.

“Oh. I take it he was the, uh, the-”

She just nodded glumly. Dipper, however, was remaining remarkably upbeat, almost excited.

“Well, tell you what. Grunkle Ford’s off on another ethereal jaunt with that big hairy alien rock lady, but when he gets back, I’ll bet you he will know exactly how to cure this. Ok?”

He ducked a finger under her chin, raising her to meet his reassuring gaze as he murmured “You’ll get through this, Mabes. I know you will.”

She smiled, the edges of her eyes starting to tear up slightly, when her stomach let out a rumbling growl. Dipper’s eyes widened, but his tone still was filled with nervous excitement.

“Oh, man, I’ve been planning for just such an occasion. Okay, so there’s a few options depending on how fresh the source needs to be, but I can lay out your options so we can get you fed and avoid any uncontrollable bloodlust-induced orgies of destruction. So, does the blood need to be fresh, or can it be a bit older and settled?”

In a weak voice, she said “Actually, it’s semen.”

On autopilot, Dipper replied “Great! So we can just collect it into a container like a balloon or condom and then when you… _eh?”_ His ears finally caught up with and kicked the rest of his brain to make him pay attention, and the resulting trainwreck ended his monologue with a squeak.

“Oh, uh…huh. Gotta say I never heard of _that_ food source before.” Mabel gave him a helpless shrug, and as he felt a flush rising, he avoided her gaze.

“So, uh, well then. I think…hmm, I think the other guys next door will be back in a few minutes from getting dinner, so I could always go over with a set of condoms, and call in the favors they owe me to have them, uh, _ohboy this is going to be awkward…”_

He trailed off as Mabel’s big puppy-dog eyes looked at him, and in  pitiful voice she said “But Dip, I’m hungry now.” She glanced from his face down to the bulge that had developed in his pants, and said quietly “Couldn’t you…well, y’know?”

He felt the flush burn through his face as he stammered. “B-but, well, we’ve never, I just. Oh man, we made out that one time, and don’t get me wrong I _really_ liked it, but this is sorta a whole different, _entirely_ different thing and I, uh, ah-”

He saw her pleading eyes, and groaned. “Ok. Fine. I’ll do it for science.” He stood, grabbing a condom wrapper from the sock drawer, and then stepping to the door. He paused, giving Mabel a quick kiss on the forehead. Then he opened the door, and strode purposefully towards the restroom as the door closed behind him.

 

* * *

 

A few minutes later, he returned, the flush now fully reaching his face, and he slid out from a pocket a wad of toilet paper. Wrapped in the middle was a tied-off condom, filled with a white fluid that had Mabel suddenly drooling over. She grabbed it, and Dipper awkwardly turned to give her some privacy as she bit into the condom, feeling her teeth pierce the rubber and then-

_Bliss._

She came to her senses a minute later, and turned to see Dipper regarding her with a wide-eyed stare.

“What?”

He coughed and swallowed. “Uh, you, uh, you were _very_ into, uh, drinking…that.”

Mabel felt a blush begin, as the warm tingling memory of the delicious ambrosia flooded through her. “Ah, uh, sorry about that Dip. I…”

Her voice trailed off, as she smelled something amazing. It smelled like the best vanilla cookies she had ever eaten, combined with the delicious scent of roasted meat on a grill, along with the sweet tartness of a sliced orange.

She turned to follow her nose, and found herself staring at Dipper’s pants. The bulge was smaller now, but oh so _wonderfully_ still present.

“Uh, Mabes? Mabel?” He waved a hand in front of her face, and her gaze snapped up to his face before drifting back to his crotch.

“Ah, oh thank you Dipper. However, I’m still very, _very-”_ She glanced at his face, licking her lips with meaning. “-mmm, _hungry.”_

Her twin nodded, coughing as the flush returned and the tent in his pants began to return, and he started to reach for the sock drawer again.

“Well, heh, I suppose I can always just pull off a repeat performance and-”

With a deep growl, Mabel pushed forward, knocking Dipper back onto his blankets as she let out a throaty moan. “Too _long.”_

Dipper stammered, his mind going all sorts of directions in shock and ecstasy, and in the meantime Mabel just slunk down his form, reaching his pants and revelling in the scent of deliciousness beyond. She unbuttoned her brother’s pants, sliding them down and off effortlessly, and a moment later his boxers followed suit.

His cock was still gleaming at the end, and Mabel felt her whole body tingle in orgasmic fire as she saw it twitch. She gently took it in one hand, pumping as she felt the skin grow firm under her palm. Dipper groaned, his hands reaching and grabbing at everything and nothing as he panted.

Then Mabel leaned forward, and gently ran her tongue around the head of Dipper’s shaft. The slight echo of flavor there was like the most potent of drugs, and she felt herself slip into that pool of hot perfection for a fleeting second before returning. She glanced up at Dipper, and smirked to herself as she saw he was panting, his legs akimbo as his eyes rolled back in his head.

She had watched her brother masturbate before, secretly, shamefully, and she had always seen how quickly and easily he had came. Now, though, he was going on three times as long as she had seen him go before, and while Dipper was clearly enjoying the experience, there was frustratingly little liquid nourishment for his sister.

_Time to fix that, then._

Mabel ducked her head down to the base of Dipper’s cock, sucking in deeply before pulling of of his cock with a _pop_ in a single motion. Immediately she ducked back, enveloping the head with hot breaths and a swirling tongue, before pulling off and trailing kisses and a teasing tongue up and down each side of his cock. She revelled in the feeling of the hardness under her fingers, and as Dipper whined and gasped and shook, she continued to run little kisses around his cock. She straightened, clearing her throat slightly, and then took his length fully in her mouth, enveloping him down to his base with a low humming groan.

Dipper let out a moan, and she felt his hands in her hair for a moment before they returned to pull at his own shirt and provide a muffle for his own gasps of pleasure to be muffled by. She grinned, and ran her tongue a but along the shaft, before pulling back to a more comfortable position and beginning to suck regularly. She worked him with long, slow strokes, as Dipper writhed on the bed. Sweat was sheening on his thighs, as she held them apart, sucking greedily as she felt him buck, his legs clamping together on the sides of her head for a moment before she easily forced them apart with her supernaturally-strong arms.

Her reward was a brief, tiny drop or two; enough for a return to the warm, white fuzziness of satisfaction, but returning from the high just as quickly.

She took him back in her mouth, ignoring the halfhearted sounds of protest he made before arching back onto his blankets.Her twin’s shaft softened slightly, but remained surprisingly rigid despite the second orgasm. She quickly dipped a finger into her jeans, running it along the dampness that had begun to leak from her excited slit, and in a smooth motion lifted Dipper up so his back thumped against the wall, her knees on the bed now as she continued to suck and rub her tongue along his hardness.

Then, with the moistened finger, she reached behind Dipper, and began pressing it against his ass. He gasped, eyes flicking open in shock, but Mabel just gave him a wink and gave an especially-long and lazy suck on his shaft. Dipper groaned, shifting with surprise, and then gasped again with shock and building pleasure as her finger slipped past the muscular resistance, and after a moment of searching, Mabel began gently pressing with the pad of the finger against a certain, particular spot.

Dipper cried aloud, quickly trying to muffle his building orgasm with a hand over his mouth, his other hand now entwined in Mabel’s hair and just holding her over his cock, as if he was afraid she might leave him then and there.

She withdrew her mouth, ignoring Dipper’s groan of protest as she began kissing along the sides with hot breaths, and ending each length with a lazy suck on just the head and tip of his shaft. Then, building the kisses faster and faster with Dipper’s panting breaths, she took his full length into her mouth at the same time as she pressed as firmly as she could with her finger.

Her brother simply squeaked, open-mouthed, as his cock began jumping, spurting and unloading a hot ropes of cum into her waiting mouth. As soon as the first load hit her tongue, Mabel could feel herself fading, and as she swallowed frantically, she lost all sense of time and space.

 

* * *

 

Mabel awoke, by the measure of the clock, some three hours later. Dipper was completely asleep, snoring, and both of their hands were wrinkled with sweat. Dipper’s balls, previously full and of a respectable size, had now retreated into his body with presumed use, and Mabel let out a little burp of satisfaction as she leaned back.

As Dipper reached over in his sleep to grab and cuddle her arm, Mabel sighed.

 _Screw “curse”: I wonder if Greta and Candy want to get in on some of this action?,_ she thought with an exceptionally pointy grin.

**Notes for the Chapter:**

> Prompt from an Anon: Mabel finally meets the vampire of her dreams, and becomes one herself. Downside, turns out that vampires don’t quite drink the bodily fluid she thought they did, which would also explain why her vampire dreamboy was so insistent that it wouldn’t work out between them. Now she finds herself drawn to her brother to sate her dark desires.


	7. Universe K45[&]rs

“So you’re telling me that, he-I mean I-or-…well, you know what I mean! You’re saying the lab was left unlocked, and so you snuck in?”

Dipper and Mabel, both still sitting in the chairs in the Shack of Mysteries, had their eyes fixed on the woman with the grey hair, the brown trenchcoat, and an all-too-familiar tic of pacing and suspicious squinting. Her voice held multiple notes of frustration, despite having only met the twins a few minutes ago.

Dipper’s eyes slid over to the kitchen table, where two more figures sat. _Well, met us only a few minutes ago. The, uh, ‘twins,’ however…_

Seated at the table was a pair of strangers that Dipper felt seemed all too familiar. The girl had a blue vest, and a hat bearing a blue oak leaf, and was matching Dipper’s gaze right back. The boy sitting next to her was eating something glittery and powdered out of a packet with a spoon, his sweater proudly displaying a dog-helicopter abomination saying something in what looked like a scribble Dipper couldn’t read.

“Uh, yeah, uh, Graunt…Juliet?” She nodded, and Dipper swallowed and continued. “Yeah, our Grunkle Ford left the lab, uh, unlocked.”

She squinted at him, and Dipper could feel her stare right through his lie and into the wood of the chair he was sitting on. He resisted squirming too much, and she straightened, eyes still narrowed.

“I doubt I would leave my lab unlocked, for any reason, in any dimension, _but…”_ She let the words hang in the air a moment. “Regardless of how you got in, you need a way home.”

Their new Graunt Juliet sighed. “I’ll be down in the lab, and get a lock on your home dimension.” She held up the sample Mabel had donated, a sticker from her own pink Sev’ral Timez sweater, and placed it carefully in a sample tube.

“Still with the shape the machine is in, it will be a couple hours at elat before we can get a lock that won’t scatter your particles across the cosmic dimensions, and leave what little of your atoms and consciousness remain to be picked over by interdimensional scavengers!”

She looked around at the stares all four teenagers were giving her, her foot unconsciously planted on the chair she had stood up from and with a hand clenched in scientific triumph. Clearing her throat, she turned to Dipper and Mabel’s dopplegangers.

“Cassie and Mason, you two keep an eye on your, uh, ‘siblings.’ Stay here, as I don’t want to have to worry about the transdimensional repercussions of you two interacting with any more matter in our universe than absolutely necessary.”

Cassie gave Dipper one final glare, and started to open her mouth to say something when Juliet nodded, and strode to the soda machine. She punched in the code, stepping behind it as it closed with a click.

There was a slow silence, and Dipper desperately wanted to talk this over with Mabel, get some bearing on the situation, but a glance at his sister saw she was staring with unabashed enamor at the packet Mason was holding. He sighed, and slumped his shoulders.

Mason was the first to break the silence.

“Sooo, you two are twins too, huh?” Dipper glanced at Mabel as she shrugged at the obvious question. He could feel his brow furrow in confusion, at the patently-obvious question, and then at Cassie’s sudden look of alarm as she reached for her brother as he opened his mouth again-

“Are you two dating too?”

Dipper’s mouth fell open in shock, as Cassie facepalmed with a groan. He could hear her mutter “Great, bro, just go ahead and blurt that out there, why don’t you?”

Dipper coughed to clear his throat as Mabel looked to him to reply, and in a halting voice he replied “Uh, n-no, of course not!”

This time Mabel’s face fell into an open hand in frustration, and Cassie’s look of worry quickly muddled to something approaching smugness. “Well, thank goodness for that. Now we can all share each-other’s secret shame, let’s sit here in silence until Graunt Juliet finishes. Okay?”

Mason just shrugged, and dipped another spoon into the packet of DippyGrin, wandering with it into the living room despite Cassie’s sudden noise of protest. Before Dipper could object, Mabel had stood to follow, the lure of the untasted candy pulling her along with ease.

He shot Cassie a look of shared frustration and embarrassment, and they both got up, following their respective twins into the living room as well. Mason had sat in the easy chair, and Mabel perched on the arm, giving Mason a big wink when he looked up with a powdered-sugar-encrusted smile.

“So, uh, Mabel, right?” She nodded, eyes not drifting from the siren call of the sugar. “Did you want to try a taste?”

She grinned, as Mabel said in a squeal filled with excitement “Thank yooouuu!” The packet was in her hands in an instant, and she gently shook a tiny pile onto her tongue as Dipper’s scientific mind kicked forward a possible concern. “Mabel, you-”

“You shouldn’t let her have some, Mason. It might be toxic, or mess up her body chemistry or something.” Cassie’s interjection cut Dipper off; he turned to look at her, but after a moment, nodded in thanks rather than voice an objection, and got a slight nod and smile in return.

Mabel made a contemplative noise as the packet was surrendered back to Mason. “Hmmm. Sweet, for sure, but there’s a lot more of a citrus-pineapple note in your version than SmileDip back home. Plus, there’s none of that immediate high like the good stuff packs.”

Mason just grinned, and held up an open hand. He closed fingers, counting down to zero, and when he had a clenched fist, Mabel leaned backwards with a low “Whooo _oooaaa,_ there it is.”

Dipper took a spot on the couch, and Cassie took the opposite cushion a minute later. He was glancing at the ceiling when he felt rather than heard Cassie scoot a few inches closer to him, and he looked to give her an awkward smile that she returned in kind.

“So, uh, how about that science, huh?”

She giggled. “Oh, definitely, very Euclidean. How about those cryptids; find any platypuses lately?”

Dipper’s gaze shifted to the clear taxidermy mishmash of a duck bill, a beaver pelt and tail, and what were clearly the half-shelled eggs of a chicken on a display behind Cassie. He grinned, and said “Actually, those are real on our side. Venomous, too.”

Cassie’s head cocked, not sure if Dipper was messing with her as she said “Wait, venom? In a warm-blooded animal?” He nodded, and she scooted forward. “Okay, you gotta tell me what you guys have myths for on your side. Do you have sharks?”

“Yup.”

“Manatees?”

“Those too, although they’re endangered.”

“Ah, that’s a shame. Have to beat them off with a stick to get anywhere tropical over here. How about-”

The conversation shifted into back and forth questions and answers, and Dipper didn’t even hear as Mabel’s head ducked close to Mason’s, presumably for some more powdered sugar substitute. He also failed to hear the husky whisper, the question intoned in a low murmur “So, I don’t use flavored lipgloss. Can I taste your choice, Mabel?” Dipper even missed the almost-pleading whisper back of “Please, Mason; call me ‘Mabes.’ And, _yes,_ try a taste if you’d like.”

However, Cassie stopped dead in the middle of a reply when she caught sight of what came next, and she put a hand on Dipper’s shoulder, nodding towards their twins. Dipper turned and gulped, more than a little jealousy flaring as he saw Mason making out with his sister, little gasps coming out as she met his hungry kisses.

“Uh, heh, ma-maybe we should move our conversation elsewhere?” Dipper nodded at Cassie’s suggestion, unable to break his eyes away, and he followed as she stood slowly, and then snuck off towards the stairs to the attic. The siblings were going at it, oblivious to all else as Dipper passed by, and started to go up the stairs.

One of them must have cracked an eye open, because Dipper paused on the steps as he heard a giggle and a faint “I think we scared them off.”

“Too bad. And in any case, there is entirely _too_ much clothes here, mister. Off!”

Following the command, Mason’s sweater appeared over the back of the chair, followed a moment later by Mabel’s sweater as well. There was some giggling, a squeak of pain, a growled curse at “ _Damn static,”_ and then the wet breathing and low murmurs resumed.

Dipper exited upstairs, following into the oddly-familiar bedroom. The sides were flipped from what he was used to, but otherwise most of the belongings were identical. Cassie had sat at her desk chair, but spun it to face the bed where Dipper took a seat. On a whim, he pulled his hat off, briefly running his fingers through his bangs and revealing his birthmark for a moment.

Cassie smiled, a shy one filled with understanding, and she mirrored his action. As she brushed back her longer bangs, Dipper could clearly see the birthmark he had pieced together earlier: it was much like his own, but two freckles smaller, and matched the constellation he had guessed earlier.

She smiled, looking at her desk for a moment before standing. Cassie took an awkward cough, and tried and failed to be nonchalant as she sat next to Dipper on the bed. He smiled back, and she seemed to relax slightly, before visibly tensing as she glanced down at the floorboards in the direction of Mason and Mabel.

Dipper felt a similar tension rise, and sighed in frustration. Feeling a bit of his brain nudge him to speak, he said softly “It’s not easy for you guys either, is it? Hiding it from your Grunkles, or Graunts, never able to hold hands and kiss and stuff outside of a room with a closed door.”

He felt his eyes water a bit as he said that, and when Cassie turned to look at him with a slow nod before glancing away, Dipper saw a similar shine in her eyes too. Her hand clenched into a fist.

“It’s never fair, is it? Apparently we don’t get a happily ever after in any dimension.”

They sighed together, and Dipper felt her hand on his and he smiled through his tears back.

 _Normally, if Mabel is feeling like this, a snuggle and raspberries on exposed stomachs tends to get the giggles flowing. But this? What-what does Mabel normally do for me?_ As he remembered, he slowly leaned forward, his free hand gently cupping Cassie’s cheek, and wiping away an errant tear with his thumb. Then he gently kissed her cheek, feeling her lean into the kiss, before she turned, meeting his lips on hers.

Her tongue was hot, desparate, darting, and her hands fumbled on the back of his vest as she sought to pull him closer. Dipper scooted forward, kissing her deeper, and feeling her hand running along his neck, sending shivers down his spine. Then the shivers morphed into something more, as her hand ran down to the ridge in his pants.

Dipper leaned back, quickly fumbling with his belt, before freeing himself down to his boxers. Cassie had done the same, her jeans quickly discarded to reveal a pair of cotton boyshorts, and with a final look and kiss deep on Dipper’s mouth, she sat up and shimmied those off too. Dipper mirrored her, sliding off his boxers to free his own shaft to spring parallel to his chest.

Cassie straddled Dipper’s chest, groaning slightly as her hand fumbled for his length, and then angled it towards her slit. With a wiggle of her hips to adjust it properly, she sat down onto his length, and Dipper felt her warm heat envelop his shaft. Cassie let out a deep moan of pleasure, mirroring Dipper’s groan, and she began to rock and pivot her hips. He felt his cock rolling into and out of her velvet grip, as she began gasping and grabbing at her chest through her t-shirt. Dipper reached up to replace her hands with his own, and Cassie shifted her hands to brace against his chest, now bouncing slightly up and down on his cock with her mouth biting her lip.

Dipper could feel his own surge start to build, earlier than he would have liked, but then he felt little vibrations from Cassie, as her hands on his chest began roaming, before leaning to brace on the bed behind her. Her pumping slowed to a long roll, as she gasped out a groan that squeaked into silence and then back into a low growl of pleasure as she shook. Dipper for his part, felt her clench and squeeze on his cock, and the added stimulus pushed him over the edge. As Cassie gasped and came, he did as well, pumping into her as she slowed and let out another moan of approval.

Then, slowly, she stopped, and dismounted her doppelganger, laying down on the bed next to him.

“Wow. Normally Mason is, well, a lot more-”

“Patient?” Dipper snickered, and Cassie joined in a second later.

Then two more voices joined the giggle festival, and the two on the bed shot upright to identify the source. Mason was standing in the doorway, Mabel held aloft in his arms and flushed as red as Dipper had ever seen her. His keen eye picked out Mabel’s distinctly bra-less nipple poking against her thin shirt, and Mason’s unbuttoned and partially-zipped fly, and the general state of excitement both of them shared.

Mabel bounded over to them, plopping onto the bed next to Cassie’s half-naked form. She tried to cover herself with a blanket, succeeding only after wresting it from Dipper’s grip as he attempted to do the same.

Instead, he had to cover his manhood with a ‘ _Y-Files’_ UFO-emblazoned pillow.

Mason nodded to the clock, showing that nearly two hours had elapsed since the twins had arrived in the wrong dimension.

“We figured that if we wanted to all have a big get-together, we should do it soonish, before Graunt Juliet finishes getting you guys fixed up to head home.”

In unison, Dipper and Cassie’s voices shared a note of suspicion as they said “What kind of ‘get-together’?”

This time Mabel shrugged, an unconvincing innocent tone to her voice as she said “Oh, y’know….Twin stuff.” She winked at them, and Dipper couldn’t help but grin. Cassie snickered, and Dipper chuckled as well when he saw Mason waggling his eyebrows at them. Dipper rolled his eyes, and said “All right, fine. What exactly do you have in mind?”

Mabel’s reply was quick and mischievous. “Well, Dip, I’ve seen the porn sites you browse, and, weeell…Mason’s definitely interested, if you are.”

Dipper felt his face burst a bright crimson, and as he looked at Mason, he got a smoldering look of lust, with a little playful nod, setting Dipper on fire everywhere he could feel from his crotch to his ears.

Cassie looked over as well, and as her face began to pinken, she murmured “Wait, Mason, does that ‘interest’ go for _both_ of us?” He just nodded, and she looked over to Mabel with a little hesitant smile, unsure if even the smile was allowed.

Mabel just leaned forward, planting a wet and lingering kiss on Cassie’s lips, before leaning back and placing another, as her mouth opened to meet Mabel’s and taste her sweetness and the musky flavor of her brother as well.

Gently holding his hand, Mason pulled Dipper to his feet, and gently pulled him to but against him with hands on the small of his back. Dipper felt his exposed shaft twitch in the breeze of the attic as well as the novel arousal, and Mason crooked his chin upwards with a finger, and met his mouth with a kiss.

The flavor was warm, sweet like Mabel’s always was, but in a way he didn’t expect. It was a few notes darker and more mellow of a flavor, and the unexpected sensation of stubble rasping lightly against his cheek caused his heart to race. Dipper, the more conservative and slow-paced section of his brain screaming in protest, felt himself unzip Mason’s jeans and let them fall to the floor. His cock was revealed, and Dipper paused to look at it; it was wider than his own, and with the hair trimmed to a careful length rather than his own unkempt curls. Mason grabbed it, gently stroking it a few times, and Dipper could see a gentle dot of precum shine at the tip.

On a whim, he knelt down, replacing Mason’s hand with his own, and he pumped it at face-level a few times, marveling at the unfamiliar heat and hardness under his fingers. Then he leaned forward, hesitantly, before taking Mason’s tip into his mouth. He tasted the salty bitter note of the precum for a moment, before it was replaced by the saltiness of sweat, and the lingering sweetness he recognized as Mabel’s signature vanilla flavor.

 _Well sis, let’s see if I can suck cock as well as you do._ He enveloped Mason’s length into his mouth, going down as far as he could while avoiding gagging, and felt Mason groan with approval, his hands gripped through Dipper’s hair. He bobbed up and down, remembering to try a bit of action moving around with his tongue. The groans continued, and Dipper gently broke free for a moment before pushing Mason to sit on the edge of the bed, before he continued to suck.

Next to her brother, Cassie whimpered as Mabel’s tongue flicked along the length of her sticky slit. Dipper’s cum had started to leak out in the aftermath, but Mabel had noticed, and focused her kisses and licking there, cleaning her and running little circles around her hood of her clit before running up and down her length.

Cassie had her hand up under her shirt, cotton shoved aside, and bra lifted to expose her breast to her own stimulation. Mabel noticed, and after a few sets of kisses and licks, she leaned up, trailing hot kisses up and past Cassie’s untrimmed curls, in a little loving circle around her bellybutton, and finally to gently suck at her nipple. She gasped, shivering at the sensation, and moaning quietly in pleasure again as Mabel drifted back down to her pussy.

This time, a hand was introduced, the fingers holding her open for Mabel’s tongue to run little teasing circles around, and then for Cassie to whimper as she felt Mabel’s finger dip into her, and then crook upwards. It encountered a soft, textured area, and pressed gently but firmly.

Cassie moaned aloud, temporarily drowning out the boys next to her, as she felt a white-hot crescendo begin to build. Mabel continued the light pressure, pushing and relaxing in pace with kisses around her slit, and fingers teasing and lightly brushing on the sensitive skin. The waves began to hit, and she felt herself wiggle, humming and pleading as she clenched her legs on either side of Mabel’s head, and finally arching her back and grabbing at whatever she could reach as the bliss hit her in full force.

Her hand met Dipper’s, and he clenched as tightly as he dared as he groaned aloud.

Mason’s cock had pushed past the first ring of muscle, as deep as he had ever dared to try himself with a finger. It was tight, uncomfortable, and yet the heat and heartbeat of the flesh pressing into him made his heart race, and he swallowed, Groaning again as Mason gave him a reassuring squeeze on his other hand, and began pushing forward again.

Dipper pressed his ass backwards, and felt Mason’s cock slowly but surely press further and further, until suddenly it slid another few inches and he felt a simultaneous sensation of pressure within an unfamiliar place, as well as the tickle of Mason’s balls against his own. He whimpered in pleasure, savoring the feeling for a moment, before beginning to arch himself forward.

His partner had noticed the motion, and Mason pulled back slightly, enough to slide his shaft back a ways without dislodging itself from the encircling muscle. He began pumping into Dipper, his hands moving to Dipper’s hips to pull him deeper and deeper against him. Dipper gasped, letting go of Cassie’s hand to brace himself against the bed, pushing up and backwards to seat Mason’s shaft even more deeply with each thrust.

The room was filled with the sound of panting, whimpers of pleasure, and the groans of orgasms as they built to their inevitable peaks. Mabel was the first to come, as Cassie’s enthusiastic tongue caused her to jolt, leg spasming as she bucked her hips upward, pressing her slit even deeper against the teasing tongue.

Mason was next, and Dipper a moment afterwards as he felt himself being filled with Mason’s hot seed. He groaned, his own cock rigid and spasming into open air as he came onto the bedsheet. Mason slowly pulled his shaft out, and Dipper felt his ass pulse in protest at the removal, the hot warmth tickling and threatening to ooze out with every motion he made. In order to minimize spillage and avoid touching the sore and happily-used orifice, Dipper just sat there, ass in the air, as he caught his breath.

Cassie was the last to come, from a combination of her fingers as well as Mabel’s, and from seeing her twin and her alter-ego spend themselves. A finger scooping up a dollop of Dipper’s warm cum and tasting the musky flavor was what triggered the groan, and then gentle shaking and panting for breath as her second orgasm of the evening roared to life.

All four of the twins slumped against the bed, and for a long minute, the only noises was the panting for breath, and the slight wet noises of still-moist bodies shifting to get more comfortable.

Then hands reached across, meeting hands both familiar and new, entwining fingers, and in a murmur, a quartet of voices spoke the same words.

“I love you guys.”

**Notes for the Chapter:**

> Prompt from @adamnemo42: Dipper and Mabel accidentally find an old experiment of Ford’s that ends up sending them to an alternate universe, one where everyone is the opposite gender. While the Dipper’s are working out how to send them back, the Mabel’s are bonding and decide that their respective twins need to loosen up a bit. Every possible combination ensues.


	8. Senseless

As Mabel finished putting the earplugs in her brother’s ears, and double-checking the blindfold was adjust to block everything, she saw the slight glow of light from her phone’s screen. They were discarded, from her and Dipper’s first round of passion, and now she was helping tease him to prepare the second session of the evening.

Or so Dipper thought.

 _“Can we come out of the garage yet?”_ read Candy’s text message, and Mabel texted back a little thumb emoticon. A minute later, and the door cracked open, revealing Candy’s face, and then Grenda’s.

“Guys!” Mabel said quietly, and came over to give them a hug. Candy was visibly humming with excitement, while Grenda was standing on one bare foot, biting her lip as she glanced at the floor. Mabel walked over to her, looking her in the eyes as she murmured “What’s up, girl?”

She uhmed for a second, before saying haltingly “Well, I, uh, we, um, I’ve not really-”

Mabel nodded, smiling. “Listen, Grenny baby, if Marius said it was ok, then it will be ok! As long as you’re still up for it, from what you’ve told me, he’s more than understanding.”

Her friend smiled weakly back at her. “Yeah, I guess you’re right. It’s just that I haven’t done something like this yet, even though we talked about it, and I think I might be getting cold feet.”

Mabel chuckled. “Well, if you’re willing to stick around while Candy gets the first turn, we can see if those feet might warm up a couple notches.”

Candy turned at the sound of her name. “I get first turn?” Mabel nodded, eliciting a muted squeal of excitement from Candy. She strode forward, and with a quick motion, unzipped the knee-length vinyl raincoat she was wearing.

Mabel let out an appreciative “ _Ooo_ ooh!” as she saw what her friend was wearing. Candy had worn a light blue sheer panty and bra set, including a matching garter belt, and the fabric covering was minimal and incredibly transparent even in the dim light of the one nightstand light in the corner. The scarlet-red trimmed drew attention to the boundaries of the material, and where they dangled from the garter belt, the clasps held a pair of sheer white leggings with lace trim up her thighs.

She turned, giving them a final wink and wide grin as Mabel noticed the little scarlet bows holding her hair in two short pigtails, and she quickly strode over to Dipper. Blind and deaf, her brother was smiling in bemusement as he felt Candy’s quick hand trace it’s way across his bare thigh; both Dipper and Mabel were naked, and slightly shining from their previous exertion.

Candy dipped down, carefully licking along the inside of Dipper’s thighs, briefly reaching the base of his half-stiff shaft with an audible giggle. Dipper giggled for a moment too, before humming in appreciation at the teasing. Then she reached down, gently teasing and tugging at his cock, and making a little “ooh” of appreciation as it started to reharden under her fingerwork.

Mabel had promised them that Dipper had endurance for usually at least three rounds in an evening if they hadn’t done the deed in a week or more, and passing on the Dipper-neck-noms for two consecutive nights was worth it to give her friends this opportunity. After all, how long had she regaled her best friends with tales of her sexual conquests by way of her brother, and the various ways he had pleased her over the years.

When she’d get to the height of those stories, they’d be practically drooling. It was only fair to at least let them experience the Little Dipper in all its glory at some point.

Candy dipper her head down with a giggle that dissolved into a hum, as she took Dipper’s cock into her mouth. Mabel could see one hand moving to stroke the base of his shaft, while her other hand was moving under her panties, her back shivering as she did so.

Her brother groaned, and Mabel felt more than a little tingle down below as she watched her brother’s blowjob, and then Candy jumped up, abandoning Dipper for a second and standing there, waiting.

Sure enough, the whimpering plea of disappointment could be heard, and he gave a pouty lip in Candy’s general direction, his moistened shaft twitching slightly. Candy was working herself faster and faster, eyes shut as far as Mabel could see from this angle, and then there was a shake of her body, and she withdrew her hand, only to step towards Dipper.

His hands were still securely fastened behind the back of the chair by Mabel’s fuzzy pink handcuffs, and so instead he scooted as far forward as he could when he felt Candy move to stand straddling him. Carefully, she guided his cock to her entrance, and gently slid onto his hardness. Mabel could both see and hear her orgasm as her body shuddered again, and making whimpering pleading noises of her own, she began to rock her hips towards those of Mabel’s brother. Her gasps were quiet, one hand bracing and holding herself on Dipper’s shoulder, and the other grabbing at the material covering her breast as she rocked faster and faster.

Soon, she was almost standing, coming back down hard on Dipper’s shaft with every downstroke, and he was pushing his hips upward with each downstroke as well. The rhythm of flesh soon was joined by Candy’s rising gasping squeaks, her shoulders starting to shiver first as the big one built. Mabel was surprised to realize she had a hand between her legs, feeling her own little tingle of excitement and promise of another white-hot explosion of pleasure in the not-too-distant future.

Glancing over, she smiled in relief. Grenda was clearly aroused, a flush visible in her face as she slowly rocked her butt back and forth on the chair, leisurely mastrubating herself while her hands gripped the arms of the chair hard enough to make them creak in protest.

Mabel’s gaze shot back to her brother and his current partner, as Dipper’s toes did the little curl they always did, and he let out a gasped “ _ohgod, ohmygod”_ as he came.

The effect on Candy was electric. She froze, her hands shooting from Dipper’s shoulder and her own visibly-erect nipples, to grasp the twin’s bare ass and pull him deeper into her, her legs wiggling slightly as she attempted to get every millimeter of him inside of her. Then a moment later, she hunched over, her head almost colliding with Dipper’s blinded face, and through gritted teeth Mabel heard a strangled scream of pleasure.

Then she began fucking Dipper again, pounding against him even as he still came, her grunts of effort through clenched teeth as her eyes remained shut, and after a few seconds of the renewed vigor, she too slowed.

Candy remained on Dipper for a long minute, coming off of the orgasm into the post-coital glow with a hum and a smile at Mabel; one of her pigtails had come undone, the ribbon off who knew where, and Candy didn’t appear to notice in the slightest. Finally, with visible reluctance, she stood, freeing Dipper’s flaccid cock with a wet slick. She collapsed onto the loveseat next to Mabel, and even as she sat her hand began to drift back down, slowly moving up and down as Dipper’s cum oozed between her fingers as she did.

In a raw whisper, she said “Grenda, your turn.”

Grenda was staring, mouth slightly open, before she closed it and set her chin, turning towards the recharging Pines twin. She stopped before she reached his chair, and turned back to Mabel, her brow furrowed.

“Mabel, I, well-Dipper will know it’s not you as soon as I start.” Her gaze shifted to Candy, who was oblivious to all else except her own hands for the moment, and then Grenda looked to Mabel. “You and Candy are about the same size and all, but I’m, well…not,” she finished, gesturing at herself in her fur overcoat with both hands.

Mabel stood, and walked over to give her a hug. “Grenda, Dipper’s probably already suspicious, and he’d figure it out sooner or later. You’re not our size, but you’re a perfect size anyways.” Grenda smiled, blinking back the slight blurriness that had temporarily muddled her vision.

“Yeah, you really think so?”

“Girlfriend, I _know_ so. Now, get on over there, make me proud.”

Grenda smiled, and then broke the hug to stand before the bound sensory-impaired Pines twin. She sighed, taking in a deep breath as she closed her eyes, and went to unbutton the coat. She felt the button catch, tangled in a loose edging thread, and with an under-the-breath roar of strength, ripped the button off, taking off all but one of the remaining buttons as well.

Grenda smiled,slowly unbuttoning the last button, and swooping the coat off of her shoulders and over one arm. Then, folding it gently, she laid it on the edge of the bed.

Mabel was surprised. Rather than go fancy or primal with her clothing or costume choice, she just had a plain satin black bra and matching silk panty. She strode over to Dipper in a single step, and took his flaccid cock in her hand, and attempted to pump.

Evidently, she must have been a bit too aggressive, as Dipper let out a slight yelp of pain and surprise. She stopped, leaning back, and turned to Mabel. Ignoring the encouraging thumbs-up she got, she asked “I want to try a trick Marius has me use when he’s soft and weak too. Mabel, can I get a drop of lube?” She extended a finger, and Mabel quickly rummaged in a drawer to find a bottle.

She deposited a large drop of the uncovered container on Grenda’s finger, and received a “Thanks,” before her friend turned back to her brother. Mabel didn’t see what she did, exactly, but her hand disappeared, and a few seconds later, her brother in quick succession yelled in surprise, started to say something in protest, and then cut off with a gurgling moan.

Whatever she had done, it had worked, and her brother’s cock was clearly erect as she leaned back for a moment before standing. Candy’s lazy gaze had clearly seen the same thing, and she let out a gurgling groan of pleasure and shuddered slightly next to Mabel.

Then Grenda stood, rolled her neck, and cracked her fingers. She reached under Dipper’s armpits, lifting him up with a startled “Wait, how, Mabel? Help?” With seemingly little effort, she lifted Dipper up horizontally with a hand under his ass and another just above the small of his back.

Then she turned, lifted one leg to straddle Dipper, and crouched slightly. Dipper, for his part, had been shocked into stillness by hands and muscles that could clearly crush him like an eggshell, and didn’t move when Grenda lifted him, guiding her to the opening she had nudged aside at the base of the panties.

There was a single grunt of effort, and Dipper was ensheathed in her in an instant. Still crouched in a squat, Grenda began to lift and lower Dipper, fucking herself with her friend’s brother. Mabel could see she was clearly exerting herself in other ways, evidenced by her irregular grunts of effort not matching her human deadlifts, and also by Dipper’s matching groans and toe-clenchings of sudden pleasures.

Looking over her shoulder, she saw Mabel’s stare of interest. “Kegels,” she grunted by way of answer, and she began to work Dipper however she was working him even harder. Dipper’s groans were little gasped pleas of _“yes”_ as his head started to lean back, his hair brushing the floor with each lift.

As Dipper panted, Grenda slowed to a stop, and straightened slightly, turning to face Mabel with a red, flushed face and assured smile on her face. Still holding Dipper between her, she said mostly to herself “Yeah, that rep set should be more than enough to help keep my tone up. Time for the big finish!”

She bit her lip, her legs ducking into a crouch as she laid Dipper gently on the floor and then squatted to envelop his entire length inside her. Her hips shifted slightly one way, and then another, as Dipper’s hips buckled and he blurted out a strangled _“fuck!”_. Mabel licked her own lips as she saw Dipper’s hips buck upwards as much as Grenda’s position allowed, and continued to do so for far longer than Mabel had thought possible. By the time he slowed, slumping to the floor, a continuous thick stream of cum was dribbling out of Grenda’s slit and down his shaft with every thrust.

Grenda stood, smiling in satisfaction, and tucked the panties back into place, catching the steady dribble of warm heat from within her. She rolled her neck again, as Candy shuddered a final time before slowly getting to her feet, wandering over to give Grenda a warm, slow kiss. Mabel stood as well, joining the kiss and hugging her two friends.

“Oh, thank you for that, Mabel. Your brother is… _wonderful_ ,” gasped Candy, a slightly shiver passing through her. Grenda nodded in agreement.

“Yeah, he’s really virile! Almost as good as Marius!” Mabel grinned at the compliment.

“Ah, shucks, no problem guys.” Her hands slipped down her friends backs, down to run a finger along their damp lingerie and against their sticky slits. Candy gasped and giggled in surprise, while Grenda just hummed appreciatively. Mabel smiled mischievously as she continued.

“You know, that’s what friends are for…”

**Notes for the Chapter:**

> Prompt from an Anon: Mabel shares her brofriend with her bgffs Candy and Grenda.


	9. Picnic in the Woods

Dipper had to chuckle a little; he had been expecting some ridiculous, extravagant affair, like Mabel used to do when they were kids.

Instead, he was taken by surprise by the simplicity: In the middle of the grassy crest of the ridge, was a red-and-white checkerboard picnic sheet, the picturesque woven basket in the middle half-open, revealing the wine bottle and one end of a baguette. Mabel was sitting there, and patted the space next to her with a smile.

He strode over, stepping over the occasional soot-blackened nurse log, the ferns and tips of infant trees catching at his jeans as he passed. A bird with a nest in a nearby alder tree tweeted aloud, the song echoing in the little clearing, but quieted as a soft breeze rustled the leaves of the alders all around. He sat by his sister, accepting the proffered glass of wine she gave him and smiling with a sip at the sweet tang of a honeyed mead; a quick glance back showed that they were clearly hidden from the Mystery Shack by the intervening trees and bushes, despite part of the ridge being visible from their attic window.

He took another sip, before triumphantly presenting the sheaf of aged papers to his sister; Mabel had started the morning with a wax-sealed envelope on his bedstand, the figure of a shooting star pressed into the purple wax. That had been cyphered, and the solution he had decoded led to another, and that to yet another. The web was using surprising cyphers that even he was barely skilled enough to break; Dipper figured she must have gotten some pointers from Grunkle Ford, and as a result of the effort for the cryptography buildup, he had expected something ostentatious, bombastic.

Even still, this quiet meal together was better, felt more appropriate than a party with dozens of people and cake and balloons. He accepted the little sandwich of cold salami and gouda between the slices of baguette, and washed it down with the last of his wine. Mabel had cozied up to him, slowly resting her back against his chest.

Dipper sighed happily, and filled the wineglass again. Transferring the glass to his left hand, he carefully held the glass between the three remaining fingers as he used the other hand to support leaning back slightly; he used the pointed grip to swirl the glass, as he leaned forward and kissed his sister on the top of her short curls.

“Love you, Mabes. This was a beautiful spot.”

She turned her head slightly back up at him. “Y’think so? I was worried you’d be expecting something big, a party or something with all the friends.”

He chuckled, and shook his head. “Nope. I had been expecting that, but this is much, much better.” He raised his glass, and Mabel clinked hers against his in a silent toast. As their bracelets slid and touched and reformed the fleeting mental bond, the silent words of the other twin echoed in each-other’s minds.

_To love and healing._

Then they broke the toast, giggling out of sheer contentment, as Mabel leaned up and snuck a kiss from Dipper. He grinned, holding the kiss, and then leaning down to engage her fully. The wineglass was placed on the grass, almost immediately tipping and spilling into the roots, but Dipper didn’t care. He used his hand to help cradle his sister’s head as he kissed her, feeling the taste of sweetness on her lips from the lipgloss and mead in concert, and her tongue darted into his mouth, stroking a little circle as she hummed happily.

Her hands moved, grabbing Dipper’s shirt, and beginning to slowly unbutton it and tease it upwards. He grinned, and leaned up slightly to free his hand and finish undoing the flannel’s buttons. His sister began gently laying lingering kisses along his chest, running a little merry and wandering path as it teased around nipples, traced up and down his ribs and over the smooth skin of his bared shoulders, before back down and around to his collarbone. Finishing the tour, she trailed the kisses up his neck, to his cheek, and then a lasting breathy kiss on his lips.

Dipper let out a hot panting breath of his own, seeing as she shivered from the heat and her own arousal, and then he cupped Mabel gingerly on her back, helping to lean her back against the picnic blanket as he quickly brushed the basket and dinner contents off to the side. The warm sunlight was starting to fade to the orange of an approaching sunset, and the dappled light that revealed Mabel provided a brilliant highlight as he moved across her, his hands flowing as best as he could manage, massaging and teasing as they brushed over her collarbone, followed by his ducked head and slightly-stubbled kisses.

He helped her shrug off her hooded sweatshirt, and then lift up the camisole undershirt off of the sensitive skin of her shoulders and back. As she did nowadays, there was no bra, and the breeze helped put a final edge on the tight arousal of her nipples. Dipper held her hand as she carefully laid flat on her back and made sure she was comfortable, before continuing his wandering massaging and kissing. His hands reached all along her arms, her chest, and finally reached her breasts. He ran his thumb in little circles around each nipple, before ducking his head to take them briefly into his mouth. Mabel gasped, her back arching slightly upwards as if to try and give her brother even more to suck upon.

Dipper broke the kiss, then kissed the smooth flesh between them, then began a line of soft, slow, and lengthly kisses on the line directly upwards. After reaching the kiss just below her chin, he finally kissed his twin on the mouth, feeling her little happy sigh and hum against him.

Then Dipper leaned back out of the kis, and trailed the tips of his fingers down her body, before reaching her baggy capris. Mabel lifted up her but, and assisted slightly as Dipper slid them off of her. She had already hooked one thumb through the purple satin panties, but Dipper nudged her hand aside. He grabbed the edges himself, tugging them in teasing increments up to her knees, and then back down to the surface of the blanket, before lifting them off of her feet and tossing it with the pants and other clothes.

He glanced over his sister, marveling again over how _perfectly beautiful she_ is. His voice had begun to echo slightly within his own mind, more of an indication than the physical sensation of the contact against his bracelet. She smiled at him, and he grinned at her.

_Alright, brobro, time for you to get naked too. It’s only fair._

He nodded, and stood. A quick and final glance back towards the undetectable Mystery Shack confirmed he was indeed unseen, and he unbuttoned the top of his pants. Giving his eager twin a wide grin, Dipper eased down the zipper with agonizing slowness, before the pants were slid down and he stepped out of them.

Finally, Dipper gave her a wink, and slid down the matching purple boxers, from the same satin material as her panties had been. He had changed into them that morning after uncovering the second clue; they were her favorite pair of his, so he wanted to surprise her in case the party he suspected was incoming didn’t stop after everybody else went home.

As his hardness twitched in the moments following being revealed, Mabel’s deep breath was audible, and her gaze shifted from Dipper’s shaft and then back to his face. He smiled, and got down facing her, leaning forward to give his sister a kiss before pulling back slightly.

Mabel shifted her leg, revealing her damp slit beneath a hairless mound, and Dipper carefully directed his cock to her opening. Keeping it there, he shifted his now-free hands to brace against the ground, and slid into Mabel to his full length in a single, long stroke.

She gasped, and he felt her clench around him in surprise and hungry desire. Dipper let it rest there for a moment, and then began to slowly ease it out. For another moment, Mabel’s hips followed, shifting herself down to keep that full connection, before pausing to let him withdraw, only to plunge it slowly and smoothly back into her again.

After the third stroke, Mabel had begun to move again, her shifting matching Dipper’s slow thrusts, and he could hear the sounds beneath the echoes of nature all around them, as he sheathed his length fully within her. Her breathing was light and quick, and with little gasps she began to emit open-mouthed and involuntary hums of pleasure, matching Dipper’s unconscious grunts of effort with each downstroke.

The motions became faster and faster, the steady rhythm of their lovemaking increasing beat by beat, until their bodies felt as one from the pressed contact of flesh upon flesh, of pleasure encircled by pleasure. Their cries were fully aloud now, no longer caring if the sounds somehow made their way to a distant hiker or voyeur,

Mabel could feel the white-hot wave lapping against her belly, the heat starting to crest and peak as she squeezed without thinking; she became aware her body was shaking, and Dipper had become still, taking in deep breaths and holding them.

Then he grunted, falling forward almost onto her, and quickly but with his signature caution, he inserted a hand under her shoulder, bracing against it as he pressed his full length into his twin and held it there.

Then Mabel cried aloud with her brother, as she felt his cock twitch and throb within her, and immediately afterwards the feeling of being filled by his seed. As her brother pumped into her, Mabel could feel the dam of restraint break, and shivering goosebumps race around her body, chasing muscle spasms as she gasped for breath with the force of her coming as well.

Dipper’s pumping and filling her slowed, then stopped, and he turned to his side as Mabel did as well. Still inside of her, they faced each-other, fingers interlocked as Mabel clenched around him appreciatively. Dipper grunted and smiled in approval, and she ducked a kiss forward again, met with equal and brief passion in return.

“Happy birthday, Sir Dippingsauce.”

He grinned, trying to avoid giggling. “Happy birthday to you as well, Lady Mabelton.”

Then he released from within her, and they both leaned back, watching as the stars began to wink bright as the sunset finished fading[.](http://pinewreaths.tumblr.com/post/149632862137/picnic-in-the-woods-epilogue)

**Notes for the Chapter:**

> Prompt, from @edward-or-ford: Making love in a private & natural setting outdoors. Slow, gentle, and beautiful. The fluffiest smut that you are capable of. :-)


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